Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: addy on 30 October 2018, 11:03:13

Title: Write up for removal of a 2ltr cylinder head.
Post by: addy on 30 October 2018, 11:03:13
Hi sorry to bother everyone.  But I was wandering if anyone can help? The wife had her car trailered home last night, with a head gasket fail, looked this morning mayo is in the rocker cover and dipstick.  I would like to do the gasket change myself. I have read and re read the Haynes manual, but it jumps all over the place and isn't very helpfull. Has anybody done a writeup, for a 2lt DOHC X20XEV, Head removal. It is in a 1995 model.  If not what is the easiest way to do it? Also would a couple of oil changes,then dropping the sump remove the sludge.

Thanks in advance, for any help. It is gratefully appreciated.

Addy
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: terry paget on 30 October 2018, 12:46:33
I sympathise. The way Haynes jumps about I find discouraging too. I presumed changing an Omega clutch was way beyond me until I read JamesCDX's guide, where he said it could be done in a morning. Since then I have changed two. I appreciate that is how Haynes has to do it, to cover so many operations in one handbook, but when I see half a dozen 4 spanner tasks to change a head gasket I give up.

I have changed a 2.2 head gasket and it wasn't too difficult. The important thing seemed to be to lay everything out carefully and put it back in order and in the right place. When I got stuck I turned to this forum and got excellent advice. If there is no forum guide, have a go following Haynes, and if in doubt ask here for advice. I have lots of photographs.
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: terry paget on 30 October 2018, 12:50:22
http://www.omegaowners.com/forum/index.php?board=13.0
There is a guide.
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: Gaffers on 30 October 2018, 13:50:56
The 4 pot is fairly straight-forward once you have the right tools.  I also recall an independant garage once quoting someone about 300 notes to do the job about 10 years ago, so what?  About 400-450 at today's rates?  Worth asking around just in case :y
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: dave the builder on 30 October 2018, 19:09:46
worth doing the water pump and cam belt while apart .
important thing about replacing a head gasket is to cure the reason it failed and check the head is not warped.
(if your 95 car is on original head gasket ,it may be just the age of the gasket but check )
I find it takes me longer to clean all the bits than it does to do the spannering  :(
and it is very important that you clean everything well .
only hard part on a 16v is replacing the valve stem oil seals (tiny collets,no room for my fat sausage fingers  ;D ) IF you bother  :-\
Mr Muscle oven cleaner and those wash up sponges with plastic scourer type stuff on one side are good (and cheap ,so if you use 2 packs ,you have not spent much)
 cleaning out the rocker cover breathers and passages takes ages ,soaking in a tote with hot detergent water ,with regular changes helps (and a blast out with pressure washer if you have one)
 Time it right and you can stick it all in the w̶i̶f̶e̶'̶s̶ ̶d̶i̶s̶h̶-̶w̶a̶s̶h̶e̶r̶ ̶ parts washer without  h̶e̶r̶ ̶k̶n̶o̶w̶i̶n̶g̶  issues  ;)
an opportunity to de-glaze the cylinder walls too

full gasket kits are cheap, new head bolts a must ,couple of oil filters ,oil changes ,new anti freeze (as it will be brass monkey weather soon  :( )
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: addy on 30 October 2018, 20:44:18
Thanks everyone for the help. Hopefully it will live again.

Addy
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: addy on 03 November 2018, 13:54:56
Read the head gasket change for 2.2.  There are a couple of things, I am not sure of.  This is the first part (If you are replacing the cambelt, pulley's, tensioner and water pump, the crank pulley needs to be removed by taking out the 4 bolts holding it on.
Be careful not to move the crank away from TDC and mark the end of the crank and pulley to return it in the correct position).Do I have to remove crank pulley to change the belt, as never seen it done by Daz on my V6's?

second query is this part. Ensure you know the TDC position of each cam for refit (take a picture - I didn't and had to work it out). Not sure what is meant by this part. As they are being removed to get to head bolts, When head is sent away will the TDC position make no difference? So if the sprocket mark matches back plate, could the cams and the sprocket be taken out as one piece?  Then refitted with the sprocket marks matching back plate for TDC?
 
Sorry if I sound stupid, just checking. I have been let down by the person who was going to take the head off, then come back and fit the skimmed head and do the timing for me. They just said scrap it, as the job is too time consuming. Sure they hate Vauxhall Omegas up here in Scotland, as soon as you mention them to local vauxhall dealers or garages, their eyes glaze over.

Thanks for any help. Knowing me probably over thinking it all ;D

Addy


Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: dave the builder on 03 November 2018, 14:25:54
You won't get the old belt off ,or the new belt on without removing the crankshaft  pulley (the pulley that drives the aux belt)

helpful linky for timing marks (http://replace-timing-belt.com/how-to-replace-timing-belt-on-vauxhallopel-calibra-2-0i-16v-1993-1997_/)

you'll probably need to un-bolt the cam sprockets to remove timing back cover  :-\
i don't remember  :-[

If your sending the head off for skimming , the'd want the sprockets off to clamp it down anyway.
you could check and deck the head yourself if not way out (i resurface my own heads ,many will disagree , i've had no issues ,even with MLS headgaskets)

important thing is to make sure all the timing marks are spot on when you refit the belt  :y so if you move the crankshaft to deglaze the bores etc while dismantled, just line back up before reassembly 
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: TheBoy on 04 November 2018, 10:01:27
A question for those that have removed a head on a 2.2, is the engine safe, ie is removing and refitted head with the pistons at TDC correct?)
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: dave the builder on 04 November 2018, 11:51:44
A question for those that have removed a head on a 2.2, is the engine safe, ie is removing and refitted head with the pistons at TDC correct?)
A "safe engine" usually used to describe  an engine that won't bend valves IF timed wrong or the timing belt snapped .
I don't think any GM 16v engine will not smash the valves after cambelt fail
some of the older 8 valves where if you where lucky.
only one piston(cylinder 1) is at TDC when you fit the belt ,though no 4 is pretty close to TDC when 1 is ,so 2 a 3 will be bottom of the stroke ,well clear of valves.
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: TheBoy on 04 November 2018, 18:20:35

A question for those that have removed a head on a 2.2, is the engine safe, ie is removing and refitted head with the pistons at TDC correct?)
A "safe engine" usually used to describe  an engine that won't bend valves IF timed wrong or the timing belt snapped .
I don't think any GM 16v engine will not smash the valves after cambelt fail
some of the older 8 valves where if you where lucky.
only one piston(cylinder 1) is at TDC when you fit the belt ,though no 4 is pretty close to TDC when 1 is ,so 2 a 3 will be bottom of the stroke ,well clear of valves.
So you can't remove/refit head (specifically the cams) at TDC then....
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: Doctor Gollum on 04 November 2018, 18:30:38
In the cambelt DVD it says to move the crank 60° on the V6 to ensure that the pistons are clear of all the valves...

Presumably a 90° crank rotation will have the same result on a four pot :-\
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: dave the builder on 04 November 2018, 18:43:46
If you want to remove and refit cams ,just make sure all timing marks are set (on cams and crank shaft)
that way , cylinder 1 will be at TDC and the valves for cylinder 1 will be closed  , so the rest of the pistons and valves will be in correct timing to miss each other
as you bolt down the cam lobes ,the cam will push valves open on some valves (2 & 3) but the pistons are down anyway on those  :y

Am I missing something TB  :-\

https://www.youtube.com/watch?v=cH7e5wxSbbQ (https://www.youtube.com/watch?v=cH7e5wxSbbQ)  :D ;D
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: dave the builder on 04 November 2018, 18:49:13
In the cambelt DVD it says to move the crank 60° on the V6 to ensure that the pistons are clear of all the valves...

Presumably a 90° crank rotation will have the same result on a four pot :-\

Oh I see now the confusion
I don't know where rotating the crank by 90 degrees would put valves or pistons , but you'd need to rotate both cams AND the crankshaft to ensure the moving parts did not fight (and there ae no timing marks 90 degrees round , so on a 4 banger, stick to the timing marks and set tensioner and all will be good
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: Nick W on 04 November 2018, 20:28:49
In the cambelt DVD it says to move the crank 60° on the V6 to ensure that the pistons are clear of all the valves...

Presumably a 90° crank rotation will have the same result on a four pot :-\


That will depend on how the timing marks are aligned; as you're not using a strobe to adjust the ignition timing, there's no real need for any of them to refer to TDC.
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: Kevin Wood on 05 November 2018, 12:31:33
On any 4 pot engine, you will have 2 pistons at TDC if any are.

TDC no. 1 will put cylinder 1 at TDC and with the valves closed, but no. 4 will be at TDC on the exhaust/intake crossover, which means valves partially open and you don't have to turn the cams far to get valve damage.

On any 4 pot, regardless of the instructions in Haynes, etc. I'd strip and rebuild with the crank at 90 degrees before TDC no.1, so all 4 pistons are half way down the bores.

On reassembly, time the cams correctly for TDC No. 1, then the last action before installing the belt is to turn the crank back up to TDC no.1. This way, as you wrestle the cams into the correct position, there is no chance of valves hitting pistons.
Title: Re: Write up for removal of a 2ltr cylinder head.
Post by: Marks DTM Calib on 05 November 2018, 16:36:24
This ^^^^^