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Chat Area => General Car Chat => Topic started by: JamesV6CDX on 23 January 2018, 07:34:20

Title: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 07:34:20
Not a help or information request as such (although all opinions welcome) - more of a rambling thread.

Currently parked on my drive is a Vauxhall Corsa, it's a 2007 'D' with the almighty three cylinder 1 litre 12 valve engine. Female owned long term, not ragged or modified, reasonable history of oil changes etc.

I was told "It doesn't start very well, and when it's going, it judders a bit. It also stalls".

Understatement of the year  ;D It will only start at WOT, and then runs on at least only two cylinders, possibly one and a half. It won't idle, and cuts out as soon as it comes to a standstill.

Fault codes stored are: lambda sensor no2 open circuit, lambda 2 heater fault, general misfire, and misfire cylinder 1.

I've not looked at it, other than this (haven't even lifted the bonnet yet) - but will do so today.

My money, in this order, is on

1) Burnt out / damaged valve
2) Ring / piston trouble
3) Coil pack
4) Plug

Doesn't use any oil, and no visible smoke from the rear.

I'll be surprised if no1 is the troublesome cylinder, though, as normally on the three pot lumps, I thought it was usually no3 that suffers.

With aches/pains/rain I won't be doing any more than removing the plugs and doing a visual inspection / compression test today, but place your bets here as to what's wrong  ::)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 07:37:44
Interestingly, four years (and only 20,000 miles ago) she paid silly money to a garage, to fix a misfire. Having seen the invoice, this includes "cylinder head removal, resurfacing, and replacement of burnt out valve(s)"

So - something causing valves to burn - running lean due to fuelling issue perhaps

Or, maybe the garage couldn't be arsed to grind the valves in properly, causing  this further premature failure through lack of heat dissipation

Or worn guides.

Who knows  ;D
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 23 January 2018, 08:03:08
Well if its not using oil then it wont be a piston or ring issue

Compression test as first job (pop the throttle body off to get it to WOT or put something on the accelerator)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 08:04:59
Well if its not using oil then it wont be a piston or ring issue

Compression test as first job (pop the throttle body off to get it to WOT or put something on the accelerator)

Will do so, and post results - first job today.

There looks to be loads of room to work, and the engine small and light, so I quite fancy taking it on as a little challenge, especially if it's likely to be limited to top end trouble :y
Title: Re: Corsa, Engine Problems
Post by: henryd on 23 January 2018, 08:30:07
Well if its not using oil then it wont be a piston or ring issue

Compression test as first job (pop the throttle body off to get it to WOT or put something on the accelerator)

Will do so, and post results - first job today.

There looks to be loads of room to work, and the engine small and light, so I quite fancy taking it on as a little challenge, especially if it's likely to be limited to top end trouble :y

If it's the same one litre lump that the Corsa C had then head removal is quite a laborious task for something so small although as said access is good
Title: Re: Corsa, Engine Problems
Post by: Nick W on 23 January 2018, 08:37:55
They're prone to intake manifold problems, which could easily be the fault. That can then cause the  HG problems that they are also known for.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 09:06:38
All plugs are covered in thick white deposits, although none are oil fouled

Compression test -

Cylinder 1 - no compression (gauge JUST moved)

Cylinder 2 - 225psi - spot on

Cylinder 3 - 95psi

So my guess of running on 1.5 cylinders was about right!

I dropped a bit of oil into number 3 to see if it would rise, but annoyingly I tripped a bit and put more than a little drop in there. The compression went up to normal at this point, however, I think this was due to the excess oil, rather than anything else, so don't think the test was at all accurate.

Any thoughts?

Obviously, the head's going to have to come off either way..... Not a job I've ever done on a chain-driven corsa
Title: Re: Corsa, Engine Problems
Post by: henryd on 23 January 2018, 09:46:06
All plugs are covered in thick white deposits, although none are oil fouled

Compression test -

Cylinder 1 - no compression (gauge JUST moved)

Cylinder 2 - 225psi - spot on

Cylinder 3 - 95psi

So my guess of running on 1.5 cylinders was about right!

I dropped a bit of oil into number 3 to see if it would rise, but annoyingly I tripped a bit and put more than a little drop in there. The compression went up to normal at this point, however, I think this was due to the excess oil, rather than anything else, so don't think the test was at all accurate.

Any thoughts?

Obviously, the head's going to have to come off either way..... Not a job I've ever done on a chain-driven corsa

There is a timing kit that you'll need to reset cams after head replacement :y

https://www.ebay.co.uk/itm/Vauxhall-Timing-Setting-Locking-TooL-Corsa-AGILA-3-Cylinder-1-0L-12V-1-2L-16V-/262513369296?clk_rvr_id=1422697562768&utm_medium=cpc&utm_source=twenga&utm_campaign=twenga&utm_param=eyJlcyI6MCwicyI6OTcyMDIzNywiY2kiOiIwM2RkZTZmY2Q5MWUzOTM1MGU3ZThkNGVjZWMwOWFkMyIsImkiOiIyNjI1MTMzNjkyOTYiLCJ0cyI6MTUxNjcwMDgxMywidiI6Mywic28iOjE1MDAsImMiOjM1NjI1fQ%3D%3D&rmvSB=true
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 23 January 2018, 10:18:21
First things first, check one of the cam shafts are not snapped (as I don't go for the two failures at once principle)
Title: Re: Corsa, Engine Problems
Post by: henryd on 23 January 2018, 10:23:14
First things first, check one of the cam shafts are not snapped (as I don't go for the two failures at once principle)

Seen the front cam snap a few times on the 1.2 but not the 1.0................yet ::)
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 23 January 2018, 11:14:35
I have seen the exhaust one go on a 1.0  :y
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 13:34:44
I'll post pictures and full update later, but for now I'm off for a hot bath, as I hurt like a hurty thing after doing that.

Anyhow, three hours work (which I've discovered is my absolute limit  >:( :'() , the head is off. Camshafts are intact.

On cylinder number 1, the exhaust valves are both black. One valve is visibly holed, which is an obvious cause of the no-compression.

Cylinder 2, the exhaust valves are covered in white deposits, and are intact.

Cylinder 3, as per cylinder 2.

The inlet valves on all pots are black which looks normal.

The fire rings on the head gasket all looked intact, and as per previous update, no overheating / pressuring was present.

I filled the inlet and exhaust ports on the head with petrol, on cylinders 2 and 3, and there is no seepage past the valves whatsoever so far

The top of number 1 piston is pretty clean. Number 2 and 3 have more deposits as expected.

So why the 90psi, on cylinder 3?  :-\
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 13:52:17
I should add, I removed the injector connectors prior to compression test, so I can't see there being any bore wash issues etc
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 15:09:13
I'll post pictures and full update later, but for now I'm off for a hot bath, as I hurt like a hurty thing after doing that.

Anyhow, three hours work (which I've discovered is my absolute limit  >:( :'() , the head is off. Camshafts are intact.
Posting in For Sale sections

Absolutely no links to your Ebay auctions, or Ebay auction numbers, or direct or indirect links to other places where it is advertised.

No posting for sale items in the 'wrong' areas to get around the postcount limits.
On cylinder number 1, the exhaust valves are both black. One valve is visibly holed, which is an obvious cause of the no-compression.

Cylinder 2, the exhaust valves are covered in white deposits, and are intact.

Cylinder 3, as per cylinder 2.

The inlet valves on all pots are black which looks normal.

The fire rings on the head gasket all looked intact, and as per previous update, no overheating / pressuring was present.

I filled the inlet and exhaust ports on the head with petrol, on cylinders 2 and 3, and there is no seepage past the valves whatsoever so far

The top of number 1 piston is pretty clean. Number 2 and 3 have more deposits as expected.

So why the 90psi, on cylinder 3?  :-\
You do leave yourself wide open  ;D


OOPS, there’s another one  ;D
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 15:10:27
I'll post pictures and full update later, but for now I'm off for a hot bath, as I hurt like a hurty thing after doing that.

Anyhow, three hours work (which I've discovered is my absolute limit  >:( :'() , the head is off. Camshafts are intact.
Posting in For Sale sections

Absolutely no links to your Ebay auctions, or Ebay auction numbers, or direct or indirect links to other places where it is advertised.

No posting for sale items in the 'wrong' areas to get around the postcount limits.
On cylinder number 1, the exhaust valves are both black. One valve is visibly holed, which is an obvious cause of the no-compression.

Cylinder 2, the exhaust valves are covered in white deposits, and are intact.

Cylinder 3, as per cylinder 2.

The inlet valves on all pots are black which looks normal.

The fire rings on the head gasket all looked intact, and as per previous update, no overheating / pressuring was present.

I filled the inlet and exhaust ports on the head with petrol, on cylinders 2 and 3, and there is no seepage past the valves whatsoever so far

The top of number 1 piston is pretty clean. Number 2 and 3 have more deposits as expected.

So why the 90psi, on cylinder 3?  :-\
You do leave yourself wide open  ;D


OOPS, there’s another one  ;D

Maybe it's lack of sleep, but you've totally lost me!  ::)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 15:36:39
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 17:07:05
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 17:26:12
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 23 January 2018, 17:32:39
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D

I'm sure it must be against the forum guidelines to have such an insufficiency of cylinders. That's what he meant. :y

Given that the engine had run very poorly and no.3 did improve with the addition of oil, I wonder if it had been previously bore-washed.
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 17:39:20
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D

I'm sure it must be against the forum guidelines to have such an insufficiency of cylinders. That's what he meant. :y

Given that the engine had run very poorly and no.3 did improve with the addition of oil, I wonder if it had been previously bore-washed.
Yes....that’s what I meant....thanks Kevin. I mean, even if you had all three running fine, it would still be three too few. ;D
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 17:40:35
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D

I'm sure it must be against the forum guidelines to have such an insufficiency of cylinders. That's what he meant. :y

Given that the engine had run very poorly and no.3 did improve with the addition of oil, I wonder if it had been previously bore-washed.

Could I test the rings by say, filling the bore with a fluid and seeing if it disappears?

Thanks, Kevin :y
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 17:42:25
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D

I'm sure it must be against the forum guidelines to have such an insufficiency of cylinders. That's what he meant. :y

Given that the engine had run very poorly and no.3 did improve with the addition of oil, I wonder if it had been previously bore-washed.

Could I test the rings by say, filling the bore with a fluid and seeing if it disappears?

Thanks, Kevin :y
Like a leak test?
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 17:43:42
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D

I'm sure it must be against the forum guidelines to have such an insufficiency of cylinders. That's what he meant. :y

Given that the engine had run very poorly and no.3 did improve with the addition of oil, I wonder if it had been previously bore-washed.

Could I test the rings by say, filling the bore with a fluid and seeing if it disappears?

Thanks, Kevin :y
Like a leak test?

Yeah. A leak down test is usually done with compressed air, but I just wondered if there was any value in an overnight fluid loss type test
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 23 January 2018, 17:43:58
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.
To tell the honest truth, my new meds don't seem to be having the desired effect.  :-[

Always best to hold your hands up and be honest in these situations.  :y
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 17:48:15
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
One of three things: Piston rings, valves or crack in the block. :y

No need to thank me  ;D
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 23 January 2018, 17:48:53
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
One of three things: Piston rings, valves or crack in the block. :y

No need to thank me, thank google  ;D
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 17:52:36
Well it isn’t the valves. Sealed tight on no3.

Mark said rings are unlikely given the absence of oil burning

So I guess it points to....  :-X

Would such a crack be visible in the bore with the piston out?

I’m not against the idea of removing the pistons now I’ve come this far :y
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 23 January 2018, 17:53:33
Yeah. A leak down test is usually done with compressed air, but I just wondered if there was any value in an overnight fluid loss type test

How about taking the camshafts out, putting the CH back on the block using the old gasket and bolts, and doing a proper leak down test? There is a big difference between 200psi+ air and fuel/oil/white spirit and gravity. Plus fuel/white spirit will end up in the sump.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 17:56:24
Not a bad shout. Camshafts already out.

Where would I get the kit to do a leak down test? I don’t have a compressor but could buy one
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 18:07:33
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
One of three things: Piston rings, valves or crack in the block. :y

No need to thank me, thank google  ;D
I was messing with engines while you were in short pants, Albs. Then they put all kinds of electric thingies and sensors in them  :(
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 18:18:54
I've managed to get my hands on the old invoice from when the engine was last given surgery for a misfire.

It reads:

"Remove cylinder head and various fittings. Strip to bear head, then send for pressure test and facing. Strip out 2 x leaking valves and re-grind, then re-assemble with new chain kit, water pump, and thermostat."

"Vehicle still has compression loss to cylinder three - customer advised of this"

Cost £1,370  ::)

So - even after the previous "head job / valve job" in the garage, it was still struggling with low compression on number three.

It's got to be a ring. Hasn't it??
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 18:19:32
I should add, this invoice was in July 2014 at 62,000 miles.

The car now has 79,000.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 18:20:59
I've no doubt with 90psi on number 3, I could put a new valve in no1, and it would run pretty ok.

But I want to get one up on the garage. And fix it properly.

Can't believe they charged £1300 and gave it back still with low compression! (well, actually I can....)
Title: Re: Corsa, Engine Problems
Post by: Andy B on 23 January 2018, 18:49:19
Sounds like it's time for a box of matches .....  ::)
Title: Re: Corsa, Engine Problems
Post by: Shackeng on 23 January 2018, 18:57:36
I suspect piston ring(s) on #3, as although I have no knowledge of these engines, a cracked block would seem less likely. Certainly its worth checking the rings on that cylinder. Do a bore check while its out as well. :y
Title: Re: Corsa, Engine Problems
Post by: Rods2 on 23 January 2018, 19:05:30
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
One of three things: Piston rings, valves or crack in the block. :y

No need to thank me, thank google  ;D
I was stealing cars and messing with the engines while you were in short pants, Albs. Then they put all kinds of electric thingies like alarms, immobilizers and motion sensors in them  :(

FTFY :y
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 19:11:50
What do I leave myself wide open to, and, why have you quoted the rules for the for sale sections in your reply?

I'm not trying to sell anything  :-\
Where have I quoted selling rules? :-\
Ahhhh....I see. Sorry, James, I have obviously copied stuff previously and, for some reason, it’s pasted itself there. Please ignore my nonsense. The thread where all of this crap was originally pasted has been deleted by one of the mods. Apologies.

Good good. So what’s causing the low compression in no3  :D
One of three things: Piston rings, valves or crack in the block. :y

No need to thank me, thank google  ;D
I was stealing cars and messing with the engines while you were in short pants, Albs. Then they put all kinds of electric thingies like alarms, immobilizers and motion sensors in them  :(

FTFY :y

 ;D
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 19:22:23
I suspect piston ring(s) on #3, as although I have no knowledge of these engines, a cracked block would seem less likely. Certainly its worth checking the rings on that cylinder. Do a bore check while its out as well. :y

Yep, agreed, thanks Chris.

Piston coming out, tomorrow :y

(I'll get chance to have a rest, then, as I'm off on holiday for a week, and the parts can all soak to break down the carbon while I'm away)

Am I right in thinking, piston being removed at BDC, undo both bolts from underneith where it meets the crank, making sure bearing cap roatation is noted, and tap out via the top?

I've never actually removed a piston!

I guess I should make sure there isn't a lip at the top of the bore, too. If there is - fine wet and dry?
Title: Re: Corsa, Engine Problems
Post by: Nick W on 23 January 2018, 19:31:46
Piston removal is done how you suggested, but with minor changes: don't tap it out, but knock it out in one go. Use a block of wood and a heavy hammer. Unless there is a very obvious step at the top of the bore(which on such a low mileage engine is VERY unlikely) leave it well alone.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 19:33:09
Piston removal is done how you suggested, but with minor changes: don't tap it out, but knock it out in one go. Use a block of wood and a heavy hammer. Unless there is a very obvious step at the top of the bore(which on such a low mileage engine is VERY unlikely) leave it well alone.

cheers, mate :y

Watch this space!
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 19:48:23
I wasn't going to mention this, as such, but it has some relevance...

This is not a "must fix the corsa" exercise, and neither is it a money making exercise (I won't make any!) - it's a self confidence building / motivational thing for me.

Many here will say, I've been here for years, and, have spannered countless cars, into the hundreds, and can find my way around an engine.

That's very true. However.

In addition to my physical injuries, which do still limit me quite a lot (Three hours this morning, and I'm really paying now) - I've been struggling psychologically. The formal diagnosis (From Harley St Consultants, as opposed to GP) is a "Major Depressive Disorder" and "PTSD".

That in itself makes me feel guilty, as in my eyes those things have always been attributed to horrific armed forces incidents, not having a smash up in a car, even at the speeds involved.

There's a lot of stigma behind it, and being in a job that's perceived as "Macho" it's difficult to talk about. In addition I am being investigated for a brain injury, as a result of regular forgetfulness, personality changes, and also damage to the central nervous system, in light of symptoms which are most young Men's worst nightmare.

I'm not asking for any sympathy as such, but just as an explanation - with this little project it's not a case of doing what's most cost effective repair wise etc, it's about taking me out of my comfort zone, getting my mind working, and getting a sense of achievement from it. My consultants (both physical and psychological) have both suggested I attempt smaller amounts of what I used to do - and I can think of nothing better than some light car fettling. It's something I have always found therapeutic, in any event.

It sounds silly, but without something to get my teeth into, that I enjoy, I often struggle to get out of bed and do the most basic of tasks .. whereas today, physical pain aside, I really enjoyed myself. Thanks for listening :y
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 19:52:25
It’s a pity you’re not a bit closer, I could give you loads of  ‘light’ jobs to do. You could service both our cars, for nowt, and perhaps do a bit of gardening, all in the cause of your recovery, of course.  ;D
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 23 January 2018, 19:57:10
It’s a pity you’re not a bit closer, I could give you loads of  ‘light’ jobs to do. You could service both our cars, for nowt, and perhaps do a bit of gardening, all in the cause of your recovery, of course.  ;D

I may have stopped charging some time ago, but there are still firm expectations for bacon sarnies, brown sauce, and decent coffee  :-*
Title: Re: Corsa, Engine Problems
Post by: STEMO on 23 January 2018, 19:59:56
It’s a pity you’re not a bit closer, I could give you loads of  ‘light’ jobs to do. You could service both our cars, for nowt, and perhaps do a bit of gardening, all in the cause of your recovery, of course.  ;D

I may have stopped charging some time ago, but there are still firm expectations for bacon sarnies, brown sauce, and decent coffee  :-*
I could run to that but, as I said, too far away. Never mind, I was only thinking of you. Too soft..that’s me  ;D
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 23 January 2018, 21:47:02
Not a bad shout. Camshafts already out.

Where would I get the kit to do a leak down test? I don’t have a compressor but could buy one

Ahh. I got my leak down kit from eBay, but unless you think you'll use it more than once probably not worth it. There are plenty more tools that you'll use more often.

This is not a "must fix the corsa" exercise, and neither is it a money making exercise (I won't make any!) - it's a self confidence building / motivational thing for me.

The problem is, how thorough do you want to be? If it were a 'special car' or if you want to do a full on job learning on a 'cheap' engine then IMHO...

You're going to take one piston out so you may as well take out all 3. It's only 4 more bolts and they will be staring you in the face so only a few minutes work. It'll allow you to inspect all the piston rings, pistons, con rods, little end bearings, gudgeon pins and block bores. If they're Ok then you can just throw it all back together. In an ideal world you'd fit new rings, bearing shells and use new bolts.

Worth getting a bore gauge - something like these :
http://www.ebay.co.uk/itm/Metric-Dial-Bore-Gauge-50-160mm-Cylinder-Internal-Bore-Measuring-Engine-Gage/252741792846?hash=item3ad895b44e:g:X-YAAOSw4DJYiifu
and
https://www.ebay.co.uk/itm/0-01mm-0-0005-Digital-Dial-Indicator-Clock-DTI-Gauge-0-25-4mm-1-UK/253373298232?hash=item3afe39b638:g:DcMAAOSwgsxaXgv3

These allow you to measure the diameter of the bores at various depths down the bores, and check for any taper or out of roundness. Its boring work (excuse the pun) but you measure the diameter at top middle and bottom of the stroke in both the X and Y directions. Ideally they should all be the same and within spec, but at 90K miles I bet they aren't.

Next pop the top ring out of each piston, and press it into the relevant bore, keeping it 'square'. Use the top of the piston to push it down the bore a few mm. Then using some decent feeler gauges measure the ring gap. The gap should be speced in Haynes, but I'd expect something like 0.1mm-0.3mm. Too little gap and the piston ring may bind when the engine gets hot. Too big a gap and it'll use oil and lose compression.

You can also measure the piston diameter (on the skirt), the piston and con rod weights (should all be balanced to within a few grams), check for gudgeon pin 'rock' measure the little end diameters etc, etc. But where do you stop?
Title: Re: Corsa, Engine Problems
Post by: Nick W on 23 January 2018, 22:05:30
Where do you stop?


Well I wouldn't have got anywhere near that far into it, even though I have the equipment to do so. I certainly wouldn't be fitting new rings unless the old ones were actually damaged, and would probably leave the bearings alone too.
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 23 January 2018, 22:46:13
I really have trouble imagining that a modern engine with less than 80k on the clock will have bottom end problems, TBH.
If the bores looked OK, I think I'd lap some new valves in and see what happens.
Title: Re: Corsa, Engine Problems
Post by: Shackeng on 23 January 2018, 22:50:04
I really have trouble imagining that a modern engine with less than 80k on the clock will have bottom end problems, TBH.
If the bores looked OK, I think I'd lap some new valves in and see what happens.

Although the garage work was suspect, I probably wrongly, had hoped that they ensured all valves lapped in when the head was off. :-\ :-\ :-\
Title: Re: Corsa, Engine Problems
Post by: Andy H on 23 January 2018, 23:28:59
Low compression on Rover V8s is often (nearly always?) due to the camshafts wearing so badly that they don't open the valves much.

Probably not relevant to the Corsa but I think it is worth having another quick look at the lobes on the camshaft(s). Also have a look at cam followers.

I suppose another possibility is that someone drove through water and got enough water in no3 to bend a con-rod :-\
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 23 January 2018, 23:43:17
Where do you stop?


Well I wouldn't have got anywhere near that far into it, even though I have the equipment to do so. I certainly wouldn't be fitting new rings unless the old ones were actually damaged, and would probably leave the bearings alone too.

Well normally yes, I'd agree. But AIUI James isn't trying to just get the car running again as quickly and cheaply as possible. He's treating it as a learning experience to help his recouperation and keep his mind active. So nothing wrong with pretending its a Rolls Royce or Ferrari engine, and doing everything "properly".

If the rings and bearings are good then re-use, but unless you check them you won't know for sure if they are Ok. Cyl #3 sounds like either top or middle compression ring is gone?

There is no info on the state of Cyl #1's rings since the valves didn't allow compression. So it's a risk to assume there is nothing wrong with the rings on Cyl #1. I accept they probably will be, but if they're not you'll have to strip it all down again (another CHG, set of head bolts etc) if/when you find out they aren't Ok.

So for the cost of a set of con rod bolts it seems sensible to me to take out all 3 pistons and check all the rings, pistons, bores and bearings. Look for damage, check the ring gaps, and use some plasti-gauge (couple of quid off eBay) to check the bearing clearances.
Title: Re: Corsa, Engine Problems
Post by: Doctor Gollum on 23 January 2018, 23:50:11
As an idea, buy a new long engine and flog the car, then rebuild the old engine as an interesting project ;)
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 24 January 2018, 08:04:30
I would check that head properly, the previous garage have clearly only 'replaced a valve or two' and not properly stripped it, checked it and lapped the valves (you may find one sticking a bit or it wont lap in, plus it can be done sat at a bench). Work on the basis they never touched it (as clearly it was shoddy work!)

These units are not known for ring or bore wear plus bore wear would be easy to spot with your finger, any ring issues and it would smoke and be using oil in my mind (maybe it was?).

I assume all the inlet etc are clear with no blockages?

Title: Re: Corsa, Engine Problems
Post by: Shackeng on 24 January 2018, 10:12:19
I would check that head properly, the previous garage have clearly only 'replaced a valve or two' and not properly stripped it, checked it and lapped the valves (you may find one sticking a bit or it wont lap in, plus it can be done sat at a bench). Work on the basis they never touched it (as clearly it was shoddy work!)

These units are not known for ring or bore wear plus bore wear would be easy to spot with your finger, any ring issues and it would smoke and be using oil in my mind (maybe it was?).

I assume all the inlet etc are clear with no blockages?

I agree, and the same would apply with a cracked block. As above, it sounds like rings and/or valves, and a check of all cylinders, rings and bores would exclude them as issues. :y
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 10:42:54
I’ve found the problem on no3  ::)

It’s quite visible.

I’ll post a full update a bit later, with photos, but need to go and shower.

In the meantime you can take guesses at what I found ;)

No more work will take place for 10 days now, as I’m off to sunny canaries tomorrow :y
Title: Re: Corsa, Engine Problems
Post by: STEMO on 24 January 2018, 11:07:54
I’ve found the problem on no3  ::)

It’s quite visible.

I’ll post a full update a bit later, with photos, but need to go and shower.

In the meantime you can take guesses at what I found ;)

No more work will take place for 10 days now, as I’m off to sunny canaries tomorrow :y
Never mind a bit later...tell us now!  >:(
Title: Re: Corsa, Engine Problems
Post by: STEMO on 24 January 2018, 11:08:33
My bet is a valve problem, BTW.
Title: Re: Corsa, Engine Problems
Post by: henryd on 24 January 2018, 11:31:03
I’ve found the problem on no3  ::)

It’s quite visible.

I’ll post a full update a bit later, with photos, but need to go and shower.

In the meantime you can take guesses at what I found ;)

No more work will take place for 10 days now, as I’m off to sunny canaries tomorrow :y

Burnt piston ::)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 11:40:03
So, here are just a couple of the strip - down:

(http://www.chatterboxuk.co.uk/corsa/1.JPG)

(http://www.chatterboxuk.co.uk/corsa/2.JPG)

Here, is a photo of the obvious cause of compression loss on Cyl #1 - Hole in an exhaust valve:

(http://www.chatterboxuk.co.uk/corsa/Valve.JPG)

Here, are pictures of what I believe to be the cause of low compression on cyl #3:

(http://www.chatterboxuk.co.uk/corsa/Piston1.JPG)

(http://www.chatterboxuk.co.uk/corsa/Piston2.JPG)

(http://www.chatterboxuk.co.uk/corsa/Piston3.JPG)

(http://www.chatterboxuk.co.uk/corsa/Debris.JPG)


Its Piston Broke - Just like me :D
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 24 January 2018, 11:51:18
Yup, that'll do it! Broken ring & ring lands, by the look of it.

Running very lean, perhaps? Detting it's nuts off and knocked a hole in the valve & piston on opposing cylinders?

Look at all that space, though. Almost as if someone stole 1/4 of the engine ;D
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 24 January 2018, 11:52:36
That burnt valve could be due to the cylinder imbalances caused by the piston  :y
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 24 January 2018, 12:13:30
Blimey! Last time I saw that it was on a Ford crossflow. ;D

Has the bore survived? Look like there's some evidence of debris picked up on the skirt below the ring land damage but hopefully a hone will see the bore usable.

What's the other bank like? Oh, hang on.. ::)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 12:43:32
The bore appears to have escaped unscathed! There appears to be a very light visible mark travelling downwards, but it’s undetectible by a fingernail. My beemer has a much worse bore mark and never had an issue.

The other bank , oh hang on  ;D

I must admit I’m somewhat nervous about installing pistons. I also don’t know how to disconnect the broken piston from the con rod in order to fit the new one.

I’m guessing the gaps on the compression rings should be 180deg apart?

YouTube videos make it look easy but I’m not sure how the reality is

Parts wise -

New piston (no doubt)

New rings for all 3 (instead of just one?)

New exhaust valves x 6 on order

Inlet valves? Not ordered yet as I know they are usually ok?

Bearings where the con rods meet the crank?

Bolts for said bearings?

Head gasket, bolts and various gaskets


Title: Re: Corsa, Engine Problems
Post by: aaronjb on 24 January 2018, 12:56:53
Looks like the wrist pin is a press-in affair (no evidence of circlip/retaining clip in the pictures that I can see) which means pressing it out before you can do the oven & freezer dance to get the new one back in, I think
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 24 January 2018, 13:11:10
Warm up the inside of the piston skirt with a hot air gun and the wrist pin should just push out (might need a light knock), repeat to fit new.

If the big end bearing looks ok, re-use it.

Bores will need de-glazing so the new rings can break in.

Your choice on how many ring sets to replace, try here for parts:

https://www.enginepartsuk.net/
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 13:12:02
Looks like the wrist pin is a press-in affair (no evidence of circlip/retaining clip in the pictures that I can see) which means pressing it out before you can do the oven & freezer dance to get the new one back in, I think

Might slip the local engineering shop a few quid to do that bit, then!
Title: Re: Corsa, Engine Problems
Post by: Nick W on 24 January 2018, 13:17:30
Refitting the piston is a matter of using a well lubricated piston compressor, and confidently knocking the piston through it with the same heavy hammer and block of wood you used to remove it.


I know you're doing the job for several other good reasons, but realistically it's time for a replacement engine.
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 24 January 2018, 13:25:33
Refitting the piston is a matter of using a well lubricated piston compressor, and confidently knocking the piston through it with the same heavy hammer and block of wood you used to remove it.


I know you're doing the job for several other good reasons, but realistically it's time for a replacement engine.

Not sure I would totally agree there, any other engine will be an unknown.

This one, with not to much expense, well be of very known condition (plus its already had a new chain and guides etc which is a common cause of noise issues).

Head gasket set, rings, piston (even second hand would do give its a modern engine), chuck it together again and its good for 100k miles (which it probably won't ever get near)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 13:40:45
Refitting the piston is a matter of using a well lubricated piston compressor, and confidently knocking the piston through it with the same heavy hammer and block of wood you used to remove it.


I know you're doing the job for several other good reasons, but realistically it's time for a replacement engine.

My concern with a replacement engine is, will it soon suffer the same problems?

Cost wise I feel it’d be easier to fix this one :y
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 24 January 2018, 14:44:37
My early copy of EPC shows circlips holding the gudgeon pin on the Z10XE engine, but the online version doesn't :

https://opel.7zap.com/en/car/s07/e/1/15-1/
https://opel.7zap.com/en/car/s07/e/1/15-2/

What these do show is there are 4 different piston sizes (99,00,01) plus an 0.5mm oversize. There are also 2 (or 3) different piston ring sizes, and 2 different big end bearing sizes. The 'garage' way is to just replace what came out with the same and throw it back together. The 'correct' way to establish what you need is to measure everything - the bore sizes using the bore dial gauge and piston ring gaps as I described yesterday, and the bearing clearances using plasti-gauge. I'd be worried about out of roundness in bore #3. If its bad then the new piston rings won't seal properly and it'll use oil and possibly blow-by.

Given #1 was producing no 'thrust' and #3 reduced thrust, and knowing that these 3cyl things need to be revved to get you anywhere, and that they're lumpy as hell at tickover I'd be checking everything I could to make sure there was no damage due to out of balance operation.

When I recently re-built my LC engine, I bought loads of measuring sticks, and the more I measured the worse it got. I knew one piston had been replaced many years ago due to a timing chain break. However, when I measured the piston masses, the new one was almost 50g lighter than the other 5. They're supposed to be a balanced set (+/- 2g IIRC). 

As pointed out yesterday, where do you stop?
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 24 January 2018, 15:00:34
That is the issue, deciding where to stop.

Anything beyond slapping the same sized replacement piston back in is going to be an engine-out job to do properly.

The car is not going to become a timeless classic that you want to keep for 20 years, and it probably doesn't have enough miles left in the rest of the car to justify doing a maximal effort job on the engine.

I would be sourcing a piston and a set of rings of the correct grade, honing the bores and putting it back together, I think. Provided the bore wear is consistent with the 80k miles covered, I think that would see it out. Yes, you could do better, that's always true unless you return the engine to an as-new state (and you can go further than that, of course!) it is worth it, in this instance? No, IMHO.
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 24 January 2018, 15:15:24
The tolerancing has improved a hell of a lot over the last 30 years and all the GM engines have this sort of piston selection.

What you will find is a 00 marked on the crown, the bore will be bob on and the factory will never have used anything other than the 00 (based on my experience of pulling far to many cylinder heads and checking bores over the years)
Title: Re: Corsa, Engine Problems
Post by: STEMO on 24 January 2018, 15:42:10
The tolerancing has improved a hell of a lot over the last 30 years and all the GM engines have this sort of piston selection.

What you will find is a 00 marked on the crown, the bore will be bob on and the factory will never have used anything other than the 00 (based on my experience of pulling far to many cylinder heads and checking bores over the years)
‘Bob on’.......now there’s a Dibnahism. ;D
Title: Re: Corsa, Engine Problems
Post by: henryd on 24 January 2018, 16:02:50
The bore appears to have escaped unscathed! There appears to be a very light visible mark travelling downwards, but it’s undetectible by a fingernail. My beemer has a much worse bore mark and never had an issue.

The other bank , oh hang on  ;D

I must admit I’m somewhat nervous about installing pistons. I also don’t know how to disconnect the broken piston from the con rod in order to fit the new one.

I’m guessing the gaps on the compression rings should be 180deg apart?

YouTube videos make it look easy but I’m not sure how the reality is

Parts wise -

New piston (no doubt)

New rings for all 3 (instead of just one?)

New exhaust valves x 6 on order

Inlet valves? Not ordered yet as I know they are usually ok?

Bearings where the con rods meet the crank?

Bolts for said bearings?

Head gasket, bolts and various gaskets

I would deffo fit full set of rings(gives you a chance to check over the other two pistons),I wouldnt be changing bearings unless they are knackered and showing copper,big end bolts will go again :y
Title: Re: Corsa, Engine Problems
Post by: Shackeng on 24 January 2018, 17:32:46
The appalling thing is that the garage put this back together and charged £1300 and change! >:( >:( >:(
Send them a pic James, and congratulate them on their work. ::)
Title: Re: Corsa, Engine Problems
Post by: Field Marshal Dr. Opti on 24 January 2018, 17:55:18
£1370 and the car was returned with no compression on one cylinder. :(

Title: Re: Corsa, Engine Problems
Post by: STEMO on 24 January 2018, 17:56:10
£1370 and the car was returned with no compression on one cylinder. :(
Woman owner. Sexism at its finest.
Title: Re: Corsa, Engine Problems
Post by: Nick W on 24 January 2018, 20:25:26
Refitting the piston is a matter of using a well lubricated piston compressor, and confidently knocking the piston through it with the same heavy hammer and block of wood you used to remove it.


I know you're doing the job for several other good reasons, but realistically it's time for a replacement engine.

My concern with a replacement engine is, will it soon suffer the same problems?

Cost wise I feel it’d be easier to fix this one :y


Those are not common problems, or a quick cheap easy fix. An engine should cost less than the necessary parts, and is much less work than reassembling what you have.


I would have taken one look at that piston(and you need to examine the others if you're keeping them) and started looking for an engine.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 24 January 2018, 20:31:30
Refitting the piston is a matter of using a well lubricated piston compressor, and confidently knocking the piston through it with the same heavy hammer and block of wood you used to remove it.


I know you're doing the job for several other good reasons, but realistically it's time for a replacement engine.

My concern with a replacement engine is, will it soon suffer the same problems?

Cost wise I feel it’d be easier to fix this one :y


Those are not common problems, or a quick cheap easy fix. An engine should cost less than the necessary parts, and is much less work than reassembling what you have.


I would have taken one look at that piston(and you need to examine the others if you're keeping them) and started looking for an engine.

Quick or easy aren’t considerations. I have all the time in the world. And I fancy a challenge. I’m finding it keeps my mind active and makes me feel better.

Cost wise,

Valves £30
Head gasket set £50
Bolts £15
Used piston £20
Ring set £40

Parts are coming in at sub £150.

Seems better to spend that and have an entirely known quantity, than some used engine that’s a complete gamble?  :-\

Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 25 January 2018, 07:39:28
What’s the best way to protect the crank journals and bores from rust while I’m away?

 coated in grease, will this do?

Car will left for ten days or so while I’m away :y
Title: Re: Corsa, Engine Problems
Post by: Doctor Gollum on 25 January 2018, 07:51:32
WD40 and cover in clingfilm :-\
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 25 January 2018, 07:56:58
WD40 and cover in clingfilm :-\

What he said.

Before refit polish them up with very fine wet and dry then some garnet paper or t-cut
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 25 January 2018, 09:31:12
Boeshield T9, if you want to get fancier than WD40..
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 25 January 2018, 10:12:23
What’s the best way to protect the crank journals and bores from rust while I’m away?

 coated in grease, will this do?

Car will left for ten days or so while I’m away :y

I'd take the piston rings off the piston(s), cover the current little end bearings in grease and re-assemble. Also lightly grease the bores and the block face to stop them rusting (assuming its a cast iron block not ally) but remember you're going to have to get it all off again afterwards so don't go nuts with it. Or put the old CHG and head back on whilst you're away.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 25 January 2018, 11:04:10
Didn’t have time to reassemble -

Bores smeared with grease

Crank journals likewise and wrapped in Cling film

Same with mating surface

Cams smeared on grease and wrapped in film

Pistons are in the house  ::)

Best I could do, running late for flight ..
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 15 February 2018, 14:38:06
Time to resurrect this one....

I’ve just taken delivery of a lot of parts.

As Mark said assume the garage did nothing.

I have a set of new valves all round. Three new pistons with rings.

New big end bearings.

Full chain kit and sprockets / guides

Head set with bolts

Big end bearings

Thermostat

Water pump

Plus lots more

If I can get new con rod bolts, assuming the weather is good, I may get the three new pistons and rings fitted tomorrow :y

Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 15 February 2018, 14:39:35
The wrist pins were a nightmare. Total nightmare. Destroyed the old pistons removing them.

On refitting, got the con rod silly hot with a blowtorch, and had a 2 second window to get them in right ::)
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 15 February 2018, 14:47:43
To remove (or fit) wrist pins you heat from inside the piston (from below).

You wont need Conrod bolts, they are not fitted that tight and certainly not to the point of creep, a little thread lock if your feeling generous.

Don't fit the sump until AFTER you have fitted the timing chain cover, seen many a leak otherwise.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 15 February 2018, 14:58:23
To remove (or fit) wrist pins you heat from inside the piston (from below).

You wont need Conrod bolts, they are not fitted that tight and certainly not to the point of creep, a little thread lock if your feeling generous.

Don't fit the sump until AFTER you have fitted the timing chain cover, seen many a leak otherwise.

Thanks mark :y

The wrist pins are fitted now. One is a little off centre. Will this be an issue?

I imagine not, as

A) it’s fixed in the conrod
b) there’s plenty of “purchase” either side of the piston regardless of any offset either side



Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 15 February 2018, 15:00:16
To remove (or fit) wrist pins you heat from inside the piston (from below).

You wont need Conrod bolts, they are not fitted that tight and certainly not to the point of creep, a little thread lock if your feeling generous.

Don't fit the sump until AFTER you have fitted the timing chain cover, seen many a leak otherwise.

Due to the engine mount and need to support the weight of the engine I will have to

A) loosely refit sump after fitting pistons

B) support weight, remove engine mount

C) refit timing gear, cover etc

D) fit and seal sump properly :y

Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 15 February 2018, 17:20:53
Just for clarity. This setup is such that the wrist pin is firmly pressed into the con rod, but runs freely on the piston skirt. So the rod can move side to side inside the piston skirt
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 16 February 2018, 08:11:07
As long as the wrist pin cant protrude from the side of the piston when the rod is slid inside the piston it should be fine.
Title: Re: Corsa, Engine Problems
Post by: Andy B on 16 February 2018, 08:15:41
Why have we gone all American ......  ::)
https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8
Title: Re: Corsa, Engine Problems
Post by: Sir Tigger KC on 16 February 2018, 09:52:41
Why have we gone all American ......  ::)
https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8

Ah yes I was wondering what the hell a wrist pin is!  ::)  ;D

Thanks for the translation Andy!  :y  Carry on James, but English please!  ;)  :)
Title: Re: Corsa, Engine Problems
Post by: henryd on 16 February 2018, 10:41:47
Why have we gone all American ......  ::)
https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8

Was thinking the same Andy ::)
Title: Re: Corsa, Engine Problems
Post by: Andy B on 16 February 2018, 13:01:24
Why have we gone all American ......  ::)
https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8

Was thinking the same Andy ::)

Unfortunately there's too much sh1te on the telly from the good old US of A and ultimately the Interweb is in American which results in English playing second fiddle.
Title: Re: Corsa, Engine Problems
Post by: Nick W on 18 February 2018, 16:25:26
Why have we gone all American ......  ::)
https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8 (https://www.google.co.uk/search?q=gudgeon+pin&oq=gudge&aqs=chrome.2.69i57j0l3.3511j0j8&client=tablet-android-samsung&sourceid=chrome-mobile&ie=UTF-8)

Was thinking the same Andy ::)


And me ::)
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 19 February 2018, 09:46:50
"Gudgeon Pin" = words used by old people.
"Wrist Pin" = words used by people born since medieval times.

 :P
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 19 February 2018, 09:49:05
Interesting as I always knew it as a wrist pin.  :(
Title: Re: Corsa, Engine Problems
Post by: henryd on 19 February 2018, 10:22:05
"Gudgeon Pin" = words used by old people.
"Wrist Pin" = words used by people born since medieval times.

 :P

Far cough :D
Title: Re: Corsa, Engine Problems
Post by: Andy B on 19 February 2018, 10:53:50
"Gudgeon Pin" = words used by old people.
"Wrist Pin" = words used by people born since medieval times.

 :P

Wrist pin is used by those that watch too much much American drivel  & watch seasons instead of series of telly programMES  ;)

Do you also have rocker panels instead of sills?  ::) https://www.carid.com/articles/rocker-panels.html  :P
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 19 February 2018, 11:32:12
Agreed. Its a gudgeon pin and that's an end of it.  :P :)
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 19 February 2018, 11:55:57
Agreed. Its a gudgeon pin and that's an end of it.  :P :)

The little end, of course. ;D
Title: Re: Corsa, Engine Problems
Post by: Andy B on 19 February 2018, 13:17:54
Agreed. Its a gudgeon pin and that's an end of it.  :P :)

The little end, of course. ;D

 ;D ;D ;D ;D
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 19 February 2018, 15:57:00
Small end actually. I must be a bit posher than you.  :P ;D
Title: Re: Corsa, Engine Problems
Post by: Bigron on 19 February 2018, 16:04:08
Have we been transported to Brobdignag?  ;D ;D ;D

Ron.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 19 February 2018, 23:06:48
Been slow progress on this, due to holiday, bereavement, bad back, and numerous other unrelated things going wrong, but I've managed to move it forward a bit, now.

As you've seen from previous posts on this thread I removed all the pistons, and number three was broken. A thorough inspection shows the bores to be as good as new. I cleaned them up with some clutch cleaner, and all the cross-hatch hone marks literally look like they've come from the factory.

I decided to replace all three pistons, with new piston rings. The old ones had engrained dirt in the ring gaps etc, and to be honest, price wise, it wasn't that much more to buy a piston included with the rings, than just the rings themselves (£30 a pop with rings).

So here are the three new pistons, out of the box:

(http://www.chatterboxuk.co.uk/pistons/new_pistons.jpg)

And here is one with the rings fitted (note, gaps not spaced yet)

(http://www.chatterboxuk.co.uk/pistons/with_rings.jpg)

You'll have noticed earlier on that I mentioned issues removing the gudgeon pins, but I got there in the end with the aid of some heat and patience -

Here are the pistons and con-rods, with the little-ends fitted

(http://www.chatterboxuk.co.uk/pistons/pistons_rods.jpg)

You can see here, there appears to be a little (albeit not excessive) wear, to the big end shells:

(http://www.chatterboxuk.co.uk/pistons/old_bigend.jpg)

So I decided to replace them all for brand new. Here is one of them:

(http://www.chatterboxuk.co.uk/pistons/new_shell.jpg)

I realised at this point I didn't have a ring compressor, so off to Halfords I trot. They had a Laser piston ring compressor which certainly looked ok, so I went for that. In hindsight, that was a mistake, but it got this job done.

At this point, I installed the number one piston. I followed the instructions in the tech data to the T, and upon advice of numerous video's I had watched, coated everything generously in oil.

Following the confident blow with the handle of my hammer, with everything lined up, it popped smoothly down into the bore with a nice satisfying little noise, leaving me with this:

(http://www.chatterboxuk.co.uk/pistons/1_piston.jpg)

Here is where the fun started.

Upon attempting the same with number two, I just felt that the compressor wasn't gripping the rings evenly. I couldn't see this, it was just a strange hunch that it was out of round.

I removed the compressor, double checked everything, and it all seemed ok, so went to fit number 2 in the same way as I did one.

This time, the piston didn't go straight into the bore. For some reason the middle compression ring didn't go in, and popped out, meaning the piston didn't go fully in.

I again removed everything, thankfully the rings were unharmed, so attempt number two, this time it went in, as did number three.

Here is the end result with the pistons fitted:

(http://www.chatterboxuk.co.uk/pistons/fitted.jpg)

As you can see, the engine is at a safe position just prior to TDC, ready for head fitment.

With the new pistons fitted, and a light smear of oil in the bores, and assembly lube used on the new bearings, the engine turns over very smoothly indeed. There is a bit more resistance than there was before, but I put this down to the fact the bearings and rings are new. There's certainly no abnormal resistance.

Next job is to rebuild the cylinder head and have a big clean up of everything.

It's going slowly, but I'll get there in the end :y
Title: Re: Corsa, Engine Problems
Post by: Andy B on 19 February 2018, 23:27:27
  ......

You'll have noticed earlier on that I mentioned issues removing the gudgeon pins, but I got there in the end with the aid of some heat and patience  ......

 :y :y :y :y ;)

Looking good. It's been a long while since I've seen that much of an engine's internals  :)
Title: Re: Corsa, Engine Problems
Post by: Bigron on 19 February 2018, 23:34:11
I'm not sure that I should admit this amidst all you experts, but back in the days of my old A30 (Austin, not the road!), I fitted the pistons without a compressor (couldn't afford one) by squeezing the rings as tightly as I could and gently offering the piston into the bore, a ring at a time, gently tapping the piston crown with a hammer handle.
I did get sore fingers, of course!

Ron.
Title: Re: Corsa, Engine Problems
Post by: henryd on 19 February 2018, 23:35:19
James,did you de-glaze the bores before fitting pistons,didn't see you mention it ::)
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 19 February 2018, 23:41:11
James,did you de-glaze the bores before fitting pistons,didn't see you mention it ::)

The chap from my local machine shop (who lives locally) popped round for a couple of beer tokens. He brought with him what I can only describe as a lot of balls on the end of a coathanger wire, that goes in a drill.

He took one look at the bores, however, and said it would do more harm than good, and to put it back together with new pistons and rings.

If he's given me duff advice then so be it, I can't see how it can possibly run any worse than it did before  :-\
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 19 February 2018, 23:46:07
The idea is that the new rings won't seal perfectly against the bores unless both wear a little on initial running, and, if the bores are smooth, that won't happen.

I'd have honed the bores regardless.
Title: Re: Corsa, Engine Problems
Post by: Bigron on 19 February 2018, 23:47:13
Oh dear, another admission - same car! I used a wooden rod with a split longitudinally to hold some emery cloth, in the chuck of a power drill. It acted like a flail and brushed against the bore quite nicely.
I bet you will say I was wrong.....

Ron.
Title: Re: Corsa, Engine Problems
Post by: Bigron on 19 February 2018, 23:48:43
I seem to remember being told, way back, that having the bores chromed and fitting chrome plated rings was a bad idea. Must be for the same reason?

Ron.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 19 February 2018, 23:50:59
The idea is that the new rings won't seal perfectly against the bores unless both wear a little on initial running, and, if the bores are smooth, that won't happen.

I'd have honed the bores regardless.

When you say won't seal perfectly.

Likely to seal well enough that the car will run to a good standard, but just not be at their best?

Or cause serious compression loss and oil problems?

I did have my doubts to be honest, but when he came with the kit to do it, he was absolutely adamant that it might do more harm than good, and I had no reason to disbelieve  :-\

If you think they need to come back out, I guess that's what my next free day will be doing!  ::)
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 20 February 2018, 09:55:16
Difficult to say what the consequences would be. You might get away with it. I'm sure it'll run fine, but you might find that it burns a little oil and, crucially, it won't ever "bed in" and improve.

He might well be right that the machine with the balls would have done more harm than good. I have used these in the past:

https://www.amazon.co.uk/Draper-56246-51-177-Cylinder-Hone/dp/B0001K9WDA?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffnt-uk-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0001K9WDA (https://www.amazon.co.uk/Draper-56246-51-177-Cylinder-Hone/dp/B0001K9WDA?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffnt-uk-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0001K9WDA)

Just run it up and down a couple of times on the end of an electric drill. Might be worth doing while you're at a stage where it won't be too much lost work.

Also, I'd put some assembly lubricant on the big end bearings when it goes together the final time just to protect them until oil pressure comes up.
Title: Re: Corsa, Engine Problems
Post by: Andy B on 20 February 2018, 09:58:39
James,did you de-glaze the bores before fitting pistons,didn't see you mention it ::)

Is that just required after a re-bore?  :-\ The cylinders are as they were
Title: Re: Corsa, Engine Problems
Post by: LC0112G on 20 February 2018, 10:00:36
Bit late now, but....

Always a good idea to put the top ring into the bore and square it up with the top of a piston, and then measure the ring gap with some feeler gauges. Gives you a crude measure of bore wear and makes sure the piston rings are the size they claim to be.

I use a paste called Graphogen for lubricating bearing surfaces on re-assembly. It stays present on initial engine starting lubricating the shells till oil pressure builds and eventually washes it out.
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 20 February 2018, 10:09:31
Clean the bores of any residue from the honing with an oily rag before fitting the pistons, of course, and it's worth putting a rag over the crank to stop any debris ending up on the big end journals.

The other thing that can sometimes be important is to check the ring end gap. I'm not sure if it's such an issue with the tolerances these things are made to these days, but sometimes when fitting new rings into a bore, there is not enough clearance at each end of the ring and they can rattle together and break the ring.

Checking this requires removing the rings from the piston, inserting them in the bore alone and measuring the end gap with feeler gauges, which is not entirely without risk of breaking them.

I'd be inclined to say that, as the pistons went into the bores easily, you might be able to wing it on that score.

EDIT: LC got there before me on the ring gaps..
Title: Re: Corsa, Engine Problems
Post by: Bigron on 20 February 2018, 10:14:45
I'm sure you already know this, but measuring the ring gap above and below the ridge at the top of the bore, plus some mathematics, will indicate the amount of bore wear (unless it's a Triumph Herald!).

Ron.
Title: Re: Corsa, Engine Problems
Post by: henryd on 20 February 2018, 11:07:55
James,did you de-glaze the bores before fitting pistons,didn't see you mention it ::)

Is that just required after a re-bore?  :-\ The cylinders are as they were

Normally glaze bust even for rings to aid bedding in,as Kevin says the rings may not bed in at all leading to oil consumption :y
Title: Re: Corsa, Engine Problems
Post by: henryd on 20 February 2018, 11:09:04
Difficult to say what the consequences would be. You might get away with it. I'm sure it'll run fine, but you might find that it burns a little oil and, crucially, it won't ever "bed in" and improve.

He might well be right that the machine with the balls would have done more harm than good. I have used these in the past:

https://www.amazon.co.uk/Draper-56246-51-177-Cylinder-Hone/dp/B0001K9WDA?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffnt-uk-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0001K9WDA (https://www.amazon.co.uk/Draper-56246-51-177-Cylinder-Hone/dp/B0001K9WDA?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffnt-uk-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0001K9WDA)

Just run it up and down a couple of times on the end of an electric drill. Might be worth doing while you're at a stage where it won't be too much lost work.

Also, I'd put some assembly lubricant on the big end bearings when it goes together the final time just to protect them until oil pressure comes up.

That link is the same kit that I have,very good they are too :y
Title: Re: Corsa, Engine Problems
Post by: henryd on 20 February 2018, 11:12:42
https://www.zoro.co.uk/shop/automotive/cylinder-head--honing-and-camshaft-tools/heavy-duty-cylinder-hone-3-leg/p/ZT1120283X?utm_campaign=pla-Automotive+-+&utm_source=google&utm_medium=shopping-pla&utm_keyword=ZT1120283X&istCompanyId=6aa6787b-063e-4414-802d-129f235df603&istItemId=wtqixxqlrx&istBid=tztx&gclid=Cj0KCQiAq6_UBRCEARIsAHyrgUyUEa3s0ZElvMlJPYIZpyhkW3sbrrai683aPMLVLGWVAKYCXwWqC7saAt1fEALw_wcB

I only added that link as I was interested to see that they recommend brake fluid as a cutting lubricant :y
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 20 February 2018, 12:28:01
You do need to knock the glaze off the bores so the rings bed in, ring gap wont be an issue (modern engine and tolerances plus they came matched to the pistons so no 'odd' supplier type issues to worry about) and there will be no bore wear (as confirmed by the cross hatch from the honing still being visible).

Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 28 February 2018, 18:16:15
A week later and still no further forward on this, haven't even lifted the bonnet. I've had a serious case of CBA, combined with the snow, and the fact I've had the funeral this week.

Tomorrow, I'm going to make a start on rebuilding the head, I think. Maybe. Unless we get snowed in, and I decide to walk the dog and have a pub lunch and some Guinness instead  ::)
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 28 February 2018, 18:35:49
Second option sounds a difficult one to resist.  8) :y ;D
Title: Re: Corsa, Engine Problems
Post by: terry paget on 01 March 2018, 16:45:38
Been slow progress on this, due to holiday, bereavement, bad back, and numerous other unrelated things going wrong, but I've managed to move it forward a bit, now.

As you've seen from previous posts on this thread I removed all the pistons, and number three was broken. A thorough inspection shows the bores to be as good as new. I cleaned them up with some clutch cleaner, and all the cross-hatch hone marks literally look like they've come from the factory.

I decided to replace all three pistons, with new piston rings. The old ones had engrained dirt in the ring gaps etc, and to be honest, price wise, it wasn't that much more to buy a piston included with the rings, than just the rings themselves (£30 a pop with rings).

So here are the three new pistons, out of the box:

(http://www.chatterboxuk.co.uk/pistons/new_pistons.jpg)

And here is one with the rings fitted (note, gaps not spaced yet)

(http://www.chatterboxuk.co.uk/pistons/with_rings.jpg)

You'll have noticed earlier on that I mentioned issues removing the wrist pins, but I got there in the end with the aid of some heat and patience -

Here are the pistons and con-rods, with the little-ends fitted

(http://www.chatterboxuk.co.uk/pistons/pistons_rods.jpg)

You can see here, there appears to be a little (albeit not excessive) wear, to the big end shells:

(http://www.chatterboxuk.co.uk/pistons/old_bigend.jpg)

So I decided to replace them all for brand new. Here is one of them:

(http://www.chatterboxuk.co.uk/pistons/new_shell.jpg)

I realised at this point I didn't have a ring compressor, so off to Halfords I trot. They had a Laser piston ring compressor which certainly looked ok, so I went for that. In hindsight, that was a mistake, but it got this job done.

At this point, I installed the number one piston. I followed the instructions in the tech data to the T, and upon advice of numerous video's I had watched, coated everything generously in oil.

Following the confident blow with the handle of my hammer, with everything lined up, it popped smoothly down into the bore with a nice satisfying little noise, leaving me with this:

(http://www.chatterboxuk.co.uk/pistons/1_piston.jpg)

Here is where the fun started.

Upon attempting the same with number two, I just felt that the compressor wasn't gripping the rings evenly. I couldn't see this, it was just a strange hunch that it was out of round.

I removed the compressor, double checked everything, and it all seemed ok, so went to fit number 2 in the same way as I did one.

This time, the piston didn't go straight into the bore. For some reason the middle compression ring didn't go in, and popped out, meaning the piston didn't go fully in.

I again removed everything, thankfully the rings were unharmed, so attempt number two, this time it went in, as did number three.

Here is the end result with the pistons fitted:

(http://www.chatterboxuk.co.uk/pistons/fitted.jpg)

As you can see, the engine is at a safe position just prior to TDC, ready for head fitment.

With the new pistons fitted, and a light smear of oil in the bores, and assembly lube used on the new bearings, the engine turns over very smoothly indeed. There is a bit more resistance than there was before, but I put this down to the fact the bearings and rings are new. There's certainly no abnormal resistance.

Next job is to rebuild the cylinder head and have a big clean up of everything.

It's going slowly, but I'll get there in the end :y
How is the little end bearing lubricated?
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 01 March 2018, 17:22:45
Here, James, I had a thought..

Have you thought about doing YouTube videos of your work on cars - instructional style? (I thought of this as I watch a series on rebuilding a Ford FE by a guy in the US) Unlikely to make you a millionaire, but might add to the therapeutic value? It'll make you work more slowly or stretch things out, and add in chunks of time editing videos sat down..

Personally I quite like watching people do work on the BoobTube, and so do a lot of others..

[edit] Y'know. Once the snow clears ;)
Title: Re: Corsa, Engine Problems
Post by: STEMO on 01 March 2018, 17:30:42
I like watching people do work, full stop.  :)
Title: Re: Corsa, Engine Problems
Post by: Field Marshal Dr. Opti on 01 March 2018, 17:39:05
Here, James, I had a thought..

Have you thought about doing YouTube videos of your work on cars - instructional style? (I thought of this as I watch a series on rebuilding a Ford FE by a guy in the US) Unlikely to make you a millionaire, but might add to the therapeutic value? It'll make you work more slowly or stretch things out, and add in chunks of time editing videos sat down..

Personally I quite like watching people do work on the BoobTube, and so do a lot of others..

[edit] Y'know. Once the snow clears ;)

Good idea. :y

It wouldn't work for STMO though. The scouse accent would make people think he has just stolen the car and is breaking it for bits. ;)
Title: Re: Corsa, Engine Problems
Post by: Migv6 le Frog Fan on 01 March 2018, 18:12:26
I like watching people do work, full stop.  :)

Altogether now "You,ll neeeeever work, again". ;D
Title: Re: Corsa, Engine Problems
Post by: terry paget on 01 March 2018, 21:28:21
The wrist pins were a nightmare. Total nightmare. Destroyed the old pistons removing them.

On refitting, got the con rod silly hot with a blowtorch, and had a 2 second window to get them in right ::)
Forgive my earlier silly question. I had not been paying attention. Now I understand how you fitted the wrist (gudgeon?) pins in the connecting rod ends, I presume the wrist pins turn in the piston without lubrication.
Title: Re: Corsa, Engine Problems
Post by: Andy B on 01 March 2018, 21:55:34
The wrist pins were a nightmare. Total nightmare. Destroyed the old pistons removing them.

On refitting, got the con rod silly hot with a blowtorch, and had a 2 second window to get them in right ::)
Forgive my earlier silly question. I had not been paying attention. Now I understand how you fitted the wrist (wrist?) pins in the connecting rod ends, I presume the wrist pins turn in the piston without lubrication.

https://en.m.wikipedia.org/wiki/wrist_pin  But the gudge0n pin was a press fit into the piston on the few times I've ever been that involved in an engine.

P.S. ..... let me guess who has added a filter ..... can we have a forum in English & not American  >:(
Title: Re: Corsa, Engine Problems
Post by: terry paget on 01 March 2018, 22:49:58
The wrist pins were a nightmare. Total nightmare. Destroyed the old pistons removing them.

On refitting, got the con rod silly hot with a blowtorch, and had a 2 second window to get them in right ::)
Forgive my earlier silly question. I had not been paying attention. Now I understand how you fitted the wrist (wrist?) pins in the connecting rod ends, I presume the wrist pins turn in the piston without lubrication.

https://en.m.wikipedia.org/wiki/wrist_pin  But the gudge0n pin was a press fit into the piston on the few times I've ever been that involved in an engine.

P.S. ..... let me guess who has added a filter ..... can we have a forum in English & not American  >:(
Thank you. That makes more sense. Still not quite clear how James assembled the gudgeon pin and its bearing within the piston and in the hot con rod little end, all in his 2 second window.
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 02 March 2018, 08:38:21
IIRC on this engine the gudgeon pin is a press fit into the conrod but floats in the piston; lubrication is most likely either via 'splash' or (if it's really fancy, which I doubt!) oiling jets that fire upward into the piston crown.

So your 2-second fitment window means getting the pin slipped through the piston and the conrod with the conrod roughly central before the conrod has chance to essentially glue itself to the pin, which would be bad if the pin was sticking half out of the piston skirt.

(Other designs would be 'fully floating' where the conrod has bearing clearance to the pin and the pin has clearance to the piston, with the pin retained in the piston by spiral clips, circlips or snap-rings, or where the rod floats on the pin but the pin is a press fit in the piston)
Title: Re: Corsa, Engine Problems
Post by: terry paget on 02 March 2018, 11:45:49
IIRC on this engine the wrist pin is a press fit into the conrod but floats in the piston; lubrication is most likely either via 'splash' or (if it's really fancy, which I doubt!) oiling jets that fire upward into the piston crown.

So your 2-second fitment window means getting the pin slipped through the piston and the conrod with the conrod roughly central before the conrod has chance to essentially glue itself to the pin, which would be bad if the pin was sticking half out of the piston skirt.

(Other designs would be 'fully floating' where the conrod has bearing clearance to the pin and the pin has clearance to the piston, with the pin retained in the piston by spiral clips, circlips or snap-rings, or where the rod floats on the pin but the pin is a press fit in the piston)
Thanks.
I used to believe that drillings in the con rod allowed pumped oil to reach the little end, but James' pictures scotched that belief.
Title: Re: Corsa, Engine Problems
Post by: aaronjb on 02 March 2018, 13:28:11
Depends on the engine - if the pin floats in the conrod then there's usually a direct oiling method (passageway in the conrod), I believe, but on a non-floating pin the rod doesn't need oiling at the top end and the piston can (apparently) live with splash oiling
Title: Re: Corsa, Engine Problems
Post by: Kevin Wood on 02 March 2018, 18:08:58
The bottom oil control ring is always scraping oil off the bore and most of this is channeled through holes in the skirt where it then dribbles down onto the gud-geon pin.

That and a ready supply of oil being thrown off the big end. Oil jets are sometimes also added, either in the block or using a passage up the conrod, often because more cooling is required.
Title: Re: Corsa, Engine Problems
Post by: Marks DTM Calib on 05 March 2018, 08:07:17
Generally oil jets are only included for cooling as it can increase oil consumption, most petrol turbos have them.

The usual oiling method for a pin that floats in the rod (and hence the rod usually has a pressed in bush), is a small hole in the top to let oil mist/spray in.
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 27 March 2018, 18:32:28
Finally found a bit of motivation to get this moving, again.

Today I jetwashed off the head and had a proper look at it. I removed the broken valve for a proper inspection - thankfully the valve seat has escaped fine :y

Unfortunately, the cup in my valve spring compressor which goes over the spring is too big, even on the smallest setting. This head is quite small, and needs quite a narrow valve spring compressor.

I am wondering if I can improvise something to fit the top of my valves, by getting some thinner tubing, and using the angle grinder.

I removed the broken valve by pressing the spring down with a 14mm spanner whilst removing the colletts with a small magnetic screwdriver, but it killed my hand, I don't fancy doing that for all 12! (And I don't fancy my chances of refitting, this way)
Title: Re: Corsa, Engine Problems
Post by: dave the builder on 27 March 2018, 21:13:35
I've  just completed completely rebuilding a corsa 1.2 (Z12xep) main & big ends,rings,head work,valve stem seals,tappets etc, (spent £400+ on parts )
getting the valves out is easy compared to trying to re-fit  :(
the collets are tiny ,there is no room to get in to put the collets in place,
 then PING ,spend half hour looking for the 2 collet sections that just fired out to who knows where.
i put the head on an mdf board with a cloth to stop the valves pushing down ,
pushed down/compressed the spring with a tube with 2 prongs fashioned with an angle grinder spring end, cloth pad the other (pushed tube with my chest ,stuck the collets to my fingers with grease to get them in place )
was a total nightmare , i have a big valve spring compressor and a small pickavant one, neither worked.
ok, so i have fat sausage fingers ,  ;D
took me all day and evening to get 16 valves (which i had lapped previously ) back in .
someone  on ebay sells 2 collets for about £6 when you loose some

i suspect your local engine  place has special tools to put the collets back and can do the job in seconds for peanuts
I would not do the valve re-assembly again without finding out how much it costs to be "someone else's problem"
Title: Re: Corsa, Engine Problems
Post by: JamesV6CDX on 27 March 2018, 21:45:10
Managed to fabricate something to fit my spring compressor from some old waste water pipe, £2 from b+q. Got three valves back in so far, works a treat.

Magnetic screwdriver and a dab of grease on the inside of the collett makes reinstallation pretty easy :y
Title: Re: Corsa, Engine Problems
Post by: Nick W on 27 March 2018, 22:15:20
Managed to fabricate something to fit my spring compressor from some old waste water pipe, £2 from b+q. Got three valves back in so far, works a treat.

Magnetic screwdriver and a dab of grease on the inside of the collet makes reinstallation pretty easy :y


Get yourself one of THESE (https://www.ebay.co.uk/i/331760209787?chn=ps&dispItem=1&adgroupid=54300448927&rlsatarget=pla-398490659256&abcId=1130076&adtype=pla&merchantid=101733399&poi=&googleloc=9045024&device=c&campaignid=1029942144&crdt=0) Which are also good for the V6 and many other DOHC engines.
I just use a smaller dab of grease on the screwdriver to move the collet into place.