Omega Owners Forum
Chat Area => General Car Chat => Topic started by: Webby the Bear on 28 February 2015, 17:57:37
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Evening guys, one trusts we're all well?
So, after 6 weeks at the garage now I've found no job that I haven't been able to do. They've trusted me with 3 clutches so far, services, exhaust replacements (poor bugger had his CAT cut off by pikeys :'(), diagnostics, tyres, brakes (my favourite job) and various other things. Got to say I'm enjoying it so much.
One thing that's annoying me. I've only ever replaced one timing belt. . . And when I did I'm man enough to say I f....d it up on my omega and as some of you know Martin and TB rescued me with their much appreciated help and eeyore was back on the road in no time.
With this fear instilled that I'm going to smoke another cylinder head :'( and the fact we sadly never did any live timing belts at college I'm very eager to learn as I want to get to the point where I can do most belts. Eventually.
So ignoring the complicated omega just for now ;) most cars that come in are FWD DOHC. So for now let's stick to this kinda configuration. I'm also aware that there are various different locking tools for various different cars. But am I right in thinking the basic principle is. . .
Remove shizzle around timing belt area e.g. Coolant bottle.
Support engine with jack n wood.
Remove aux belt and whatever's in front of timing belt cover
Remove drivers side mount
Remove cover(s)
Rotate crank til cam marks line up.
Shove in crank lock.
Shove in cam locks (remove valve cover if a ford as I know they need that rear bar)
Remove tensioner and idlers if applicable
Remove belt
Replacement is reverse of removal.
Couple of questions if huge above is correct. . .
Tensioners. . . Are they mostly those that you stick an Allen key in and then tighten lock nut up when belt deflection is correct?
If belt isn't marked how do you know if you've got the belt on correctly?
Cheers boys. :y
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A lot of modern cars have self loading tensioners :y
I have really enjoyed following your journey through college etc :y
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Unless you're doing them at home would not the garage you're at have some kind of transmission/engine support as opposed to a jack and block of wood?
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Unless you're doing them at home would not the garage you're at have some kind of transmission/engine support as opposed to a jack and block of wood?
Like this
(https://www.machinemart.co.uk/images/library/product/medium/04/040814842.jpg?2)
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Any good garage will have Autodata, either online or DVD. If you go to the timing belt replacement part, there will be basic step-by-step instructions for each application, including deflection and tightening torques and tolerances.
Look up your Omega for an example as you know what that one looks like and how it goes together.
No mechanic knows every setting or every remove/replace instruction for every car, so they shpild all check it every so often.
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No mechanic knows every setting or every remove/replace instruction for every car, so they shpild all check it every so oftenwhen it all goes horribly wrong.
Fixed for reality ;D
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Thanks boys. and thanks James, it's been a long ol' journey ;D
yeah you are spot on, they do have tranny jacks and engine braces.,..but either way you get the point ;)
that's a great shout about Autodata and I have used it in the past, just I do remember the odd diagram being a tad complicated to understand (I am not thick but im not a genius either ;D). ive got one on a K Series coming up (for a mate on his drive) so that'll be my next one unless they get anymore in the shop (only had one on the 6 weeks I been there)
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More power to you for wanting to learn,being prepared to get stuck in and not being afraid to ask for help and advice.Good on yer Webby.
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First multivalve engine I did was a k series, actually a very good place to start :y :y
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More power to you for wanting to learn,being prepared to get stuck in and not being afraid to ask for help and advice.Good on yer Webby.
:y :y
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Well done on having a go mate :)
My first multivalve engine was the Vectra I had before the Omega I have now... The Omega belt was easier TBH :)
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Thanks boys really nice comments :y
When one comes in I'll ask if I can shadow the head mechanic doing it :y wil try and get some pics :)
Out of interest. . . As a mechanic you supply your own tools and the garage supplies the big stuff like bearing presses, tyre machines etc. well do mechanics provide their own locking tools for different makes or should the garage have a set of the most common lock tools? :-\
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Wouldve thought the garage would supply locking tools as they can be quite expensive especially for the amount of locking tools needed... Just don't let them buy the cheap stuff thats made from plastic...
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Sad thing is engine designers/manufacturers are lazy making us have to use cam locks etc to keep everything in place. I had a Civic and that was great - turn the engine until you could slip a couple of 8mm drill bits or other suitable rods through the pulleys and into the corresponding holes in the block and hey presto. Little MX5 has hexagon sections on the camshafts - just get to TDC and use a couple of wrenches on the hex and clamp them together with a G-Clamp or mole wrench and the cams are locked, just need to keep the timing mark on the cam sprocket aligned then. That is good design with some forethought about ease of servicing.
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Yes and no, so for the four pots that pretty much the case, can be done with a three quid tool or other item. The V6 is a more advanced due to the need to get the timing between banks correct.
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Yes and no, so for the four pots that pretty much the case, can be done with a three quid tool or other item. The V6 is a more advanced due to the need to get the timing between banks correct.
And yet Honda manage on the quad-cam, VTEC V6 in the NSX. All that's required are the timing mark on the crank, and 4 6mm pins to lock the cams and provide the timing. The belt is tensioned similarly.
Access is poor though!
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Yes and no, so for the four pots that pretty much the case, can be done with a three quid tool or other item. The V6 is a more advanced due to the need to get the timing between banks correct.
And yet Honda manage on the quad-cam, VTEC V6 in the NSX. All that's required are the timing mark on the crank, and 4 6mm pins to lock the cams and provide the timing. The belt is tensioned similarly.
Access is poor though!
That's where Hondas fixed price servicing comes into play :y From a servicing point of view the NSX cost the same to service at a main dealer as an Accord :)
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Yes and no, so for the four pots that pretty much the case, can be done with a three quid tool or other item. The V6 is a more advanced due to the need to get the timing between banks correct.
And yet Honda manage on the quad-cam, VTEC V6 in the NSX. All that's required are the timing mark on the crank, and 4 6mm pins to lock the cams and provide the timing. The belt is tensioned similarly.
Access is poor though!v
The old v6 honda engined rovers didn't new any special tools either,just line up all thee marks and go for it.
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We got a timing belt in this week. I don't know what it is yet but I'm going to do it whilst the tech has a break, I mean watches my efforts lol
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Keep up the good work Mr The Bear! :y
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I'd add to your list a lot of moving the engine up and down, usually by trolly Jack and wood under the sump, to access various bits of the belt run, due to the wheel arch structure being in the way. Focus and tigra come to mind, although it was while ago now.
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True of pretty much all transverse engine designs Chris although its more down to the need to remove the engine mount at that end.
As for the V6 timing, its all about what design compromise you want to take, clearly, removing the ability to dial in timing is a compromise which yields minor benefits in servicing, it also pretty much removes the ability to skim a head and get the timing right after (I recall the heads were advised not to be skimmed on these come to think about it).
Good design has nothing to do with servicing (as hard as it may be to swallow that bitter little pill)
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The one thing I like about our 1.8 Vectra B is it has clearly been put together with routine mainternance in mind (probably for the fleet market). Sump drain can be accessed without having the car on ramps, the oil filter is on the front of the block and easy to get at, and the timing belt can be changed without removing the engine mount and jacking up the block. Easy(ish) access too with a removable plastic inner wing panel. Not so for the aux belt though which has a very convoluted route and needs the engine mounting off to replace - just the ticket on a wet and windy night >:(
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Although the (normally goosed) engine stabiliser mount has to come off :y
To be honest, most of the VX engines are the same, the only variation being the stabiliser is replaced by an engine mount, not hard to remove and the supporting of the engine is easy enough :y
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The old v6 honda engined rovers didn't new any special tools either,just line up all thee marks and go for it.
Old being the operative word, perhaps?
The setup on the Omega is hard(er) work because, as Mark said, it allows adjustment down to sub-tooth accuracy. If you accept that the timing will be approximate, especially after a head skim, then you can of course have a setup where you just line up the marks and slap the belt on, and this was the case with most early belted engines IME.
More modern lumps, the Ford Zetec and the GM V6 being the examples that come to mind, have a fine cam timing adjustment, albeit through different implementations. Why did the designers decide that this is required? Not sure. Maybe they perceived it as necessary for reasons of fuel consumption, refinement, emissions - who knows? I'm pretty sure they would have eliminated it if they felt they could, though.
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The old v6 honda engined rovers didn't new any special tools either,just line up all thee marks and go for it.
Old being the operative word, perhaps?
The setup on the Omega is hard(er) work because, as Mark said, it allows adjustment down to sub-tooth accuracy. If you accept that the timing will be approximate, especially after a head skim, then you can of course have a setup where you just line up the marks and slap the belt on, and this was the case with most early belted engines IME.
More modern lumps, the Ford Zetec and the GM V6 being the examples that come to mind, have a fine cam timing adjustment, albeit through different implementations. Why did the designers decide that this is required? Not sure. Maybe they perceived it as necessary for reasons of fuel consumption, refinement, emissions - who knows? I'm pretty sure they would have eliminated it if they felt they could, though.
Maybe but a cracking engine that was also oil tight ::) ;)
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So watched one of the mechanics do a timing belt replacement on a 1.6 Octavia (far-king shed!!! ::)) after the HG was replaced.
Anyways, as it was his job I couldn't really say ''mind if I nick it off you'' so I decided to hang about and be annoying ask some questions...
So the timing mark for the crank was on the crank sprocket as opposed to the pulley (there could have been one on the pulley but for the part that I watched he'd got the crank mark lined up on the sprocket).
I forgot to ask where the mark was on the cam but I presume as itsa SOHC there'd be a mark on the rear cover perhaps at the 12 o clock position?
Anyway tensioner was a two pin special tool affair. he didn't have one so I think he made one. this was used to get the tensioner mark between two points, hold it there and then torque the tensioner nut (similar to the v6 tensioner)
the last thing I asked was as the belt had no markings how'd ya know if youre a tooth out...he said he'd turn the engine over a few times. if it went out of time he would know he was a tooth out. if it stayed timed bang on he knew it was good. is this correct?
The whole thing if I'm honest looked like a complete ball ache as the tensioner marks were underneath so you needed a mirror in a limited access space (being transverse) whilst holding it in the right place whilst then tighteming the nut...... you need 7 hands and only having one ill prob be f....d ::) ;D
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ps, I think this was the set up (from memory so don't beat me down if its not the correct one...
http://workshop-manuals.com/skoda/octavia-mk1/images/octavia-mk1-2113.png
which way would you feed the belt up? it makes sense to me that you'd feed it up the right hand side as the water pump is fixed in place and thus you put the belt on nice n taught... and then the ''floppy side'' gets sortedwhen you tension it?