Problems with a new timing belt

Problems with a new timing belt

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JohnL

Original Poster:

1,763 posts

272 months

Wednesday 5th February 2003
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Just had the timing belt on my Vauxhall Omega 3.0 V6 changed. As soon as I started it up on collecting it, it sounded clattery and rough, and was a lot louder than it was before. Performance was also down a bit.
It quitened down a bit when it had warmed up but still isn't a smooth and quiet as it was. They said, if it's still doing it in a couple of days bring it back.

My diagnosis is that they mis-aligned the various wheels etc when putting the new belt on, and the solution is simple: get the dopey b@ggers to take it off again and put it back properly. Does that sound about right?

And in the meantime, will it damage the engine to drive the car for the 150 miles I'm going to have to do tomorrow, let alone the 25 back home today?

deltaf

1,384 posts

264 months

Wednesday 5th February 2003
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John L did you have this belt changed by a dealer?
If you did then youve got a comeback, if not, i dunno.
These engines are critical on line up of the belt.
Theres noway it shouldve been clattering after just having the belt done, and that indicates piston to valve contact and bent valves, which is why performance is down, not to mention the timing issues involved here.
My advice is DO NOT drive it anywhere, as if indeed the valves are bent, a situation could arise where you have a valve head break off and itll likely destroy the engine.
If it was a dealer, id get in touch with their head office and speak to the guy in charge, as most dealers will just fob you off on a return like this.
Dont fall for it, and demand satisfaction.
If theyve screwed it up make them fix it.
Also, dont allow them to just swap the belt back to its correct position cos the valves will still be bent and these can then fail long after youve had it back, and the engine will have to be stripped partially to rectify this in any case.
Hope this helps.

deltaf

1,384 posts

264 months

Wednesday 5th February 2003
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Ps, trading standards may help if its a backstreet place.

JohnL

Original Poster:

1,763 posts

272 months

Thursday 6th February 2003
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Bloodyhellfire, I'd thought it would just be a matter of swapping the belt back to the right place. But you reckon the valves may have already taken a battering from what I assume is only a slight misalignment? Is there any way to tell what conditon the valves are in without removing the cylinder heads (a MAJOR operation on this car)? If they reposition the belt and it sounds like a car again instead of a taxi would that suggest the valves are OK?

It's a fairly small outfit, not a main dealer, but they've done a lot of good work for me in the past.

Well I won't be driving it to Glasgow tomorrow! I'll just put the wheels back on the MR2 and take it off the axle stands ... I don't think it'll matter not having a bumper cover, I've FINALLY got the bl00dy thing off (so that I can deal with a load of rust), the state of the rusted-to-fcuk bolts holding it on ... I used a hacksaw among other tools ...

PS don't worry it's taxed, MOT'd and insured!

>> Edited by JohnL on Thursday 6th February 00:18

pawsmcgraw

957 posts

265 months

Thursday 6th February 2003
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sounds like its one tooth out on the belt.It is not possible to bend valves if its only 1 tooth out,but it will run poor.It can ding a valve though if you rev its nuts off while its one tooth out...you would know if you had contact as it would'nt start again.
So i've just been told!

deltaf

1,384 posts

264 months

Thursday 6th February 2003
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It is possible to bend the valves.
They only have to make slight contact and the damage is done.
Theres no way to know if /how badly the valves are bent, short of head removal.
You could take a chance on having the belt re-aligned, its always possible you may have gotten away with it.
The problem i have with the no damage theory is why did the noise quieten down after itd been run?
As if the valves had been hitting, bent them, and so they clear the piston once again.
Go ahead and have the belt re done John, but get a compression check/leakdown test done to see if theres any valve problems as result of this cock up.
Its the only way i can see that you can test for valve probs without a major stripdown.
Got me fingers crossed 4 ya.

JohnL

Original Poster:

1,763 posts

272 months

Thursday 6th February 2003
quotequote all
I just had a chat with a friendly Vauxhall dealer - he reckoned that it is very unlikely to have damaged the valves, and if it had it wouldn't start. But he says to get it sorted right away and drive it as little as possible until then because it may be a tensioner etc, and the belt could come off, with "funny money" consequences.

It runs noisy when cold, quieter but still not "quiet" when warm. Two cold starts like this, same both times. So I reckon its unlikely to be valve damage (phew!). However - coul dmost garages do a compression check/leakdown test? What's a leakdown test?

Meantime I seem to have blown the head gasket on my MR2!

grahambell

2,718 posts

282 months

Thursday 6th February 2003
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JohnL said: I just had a chat with a friendly Vauxhall dealer - he reckoned that it is very unlikely to have damaged the valves, and if it had it wouldn't start.


No necessarily. It is possible to bend valves slightly due to a one tooth misalignment without preventing the engine from starting or running. It just wouldn't run as well as it should due to the cam timing being out and the compression being down because the valves weren't sealing properly.

That's what the 'leakdown test' for. Basically involves using a fluid to see if there's any leakage past the valves.

Never done one with the head on, but you should be able to do it by pressurising each port in turn (with that valve closed) and then leaving it for a short time to see what happens. No pressure drop says the valve is sealing OK, pressure drop indicates a leak, which says it isn't.

Don't know if the main dealers can actually do something like that with the engine in (they'd have to take the manifolds off at least) but might be worth asking.

Traditional method is to stick head on bench with all valves closed and fill combustion chambers with parrafin or similar, then look for signs of leakage down into the ports.

Edited to add that it's just occurred to me that you probably could do it with the engine in place without having to remove anything by using the engine's compression to pressurise the cylinder and using a compression tester to monitor the pressure.

>> Edited by grahambell on Thursday 6th February 17:22

deltaf

1,384 posts

264 months

Thursday 6th February 2003
quotequote all
The compression checks a good idea graham but itll read wrong due to the belt being fitted wrong, (incorrect cam timing).
The leakdown test basically pressurises the cylinder under test( both valves closed) and measures the percentage of air being lost due to rings or valves.
Safe to say that it was ok before, so any erroneous readings will be down to the valves id say.
Dont like the idea that its making noise on start up and then going quiet, sounds bad to me.
You could try a specialist tuner or maybe the dealer would have this gear, they should really, but might not have.
Take a look in your yellow pages or thompson local for specialist engine tuning etc and ask them if they can do a leakdown test for you.
You aint having too much luck with cars are ya mate?
Sorry to hear bout the Mr2 problem.

JohnL

Original Poster:

1,763 posts

272 months

Thursday 6th February 2003
quotequote all
Presumably then if I got the belt put ion right then a compression test with the engine in place would show if there was a problem with the valves?

Not wildly concerned about the MR2, got home with lots of top-ups of water. A new head gasket is one of the risks you take when you buy a car with 165k on the clock for £220 But yeah a bit of a run of bad luck just now.

Might not be selling the Impreza for a while though after all!

>> Edited by JohnL on Thursday 6th February 18:37

grahambell

2,718 posts

282 months

Thursday 6th February 2003
quotequote all

JohnL said: Presumably then if I got the belt put ion right then a compression test with the engine in place would show if there was a problem with the valves?


Not the compression test so much as the leakdown test. But yes, you should get the belt alignment put right first. Otherwise, as deltaf mentioned, the cam timing will be out and you might not be able to get inlet and exhaust valves fully closed at the same time like they should be, which will obviously give you a false reading.

JohnL

Original Poster:

1,763 posts

272 months

Friday 7th February 2003
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Well it's now back at the garage being sorted. I hope. The bloke was sure he'd got the timing right, and thought it may be the backing plate not tightened/positioned right - but was going to check it all.

Assuming that's some kind of cover, it could fit in - the heat once the engine's warm could make it distort out of the way. I just hope he's right!

harryW

15,276 posts

276 months

Friday 7th February 2003
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Ah found the right thread
John as part of the timing belt change it's worth getting the tensioner and the rollers changed with these VX V6 lumps. It all come as a kit and doesn't cost the earth (assuming that is they haven't already dione this for you). There was a period when the rollers in particular could fail leaving you with a very dead engine . Worth asking about whilst its in the garage.

Harry

JohnL

Original Poster:

1,763 posts

272 months

Friday 7th February 2003
quotequote all
OK that's you and two different vauxhall dealers have all said the same thing. So I've just phoned the garage, they reckon that the extra work to put the rollers and tensioner in, given what they're going to have to do anyway, will be small - so they're going to do that. It means I won't get the car back until Monday (time to order the parts), but I still have one car that works (that was going to be the one to sell, I may change that plan yet)!

HarryW

15,276 posts

276 months

Friday 7th February 2003
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Thats good, the rollers are really just cheapo lumps of plastic that 'guide' the cam belt around the corners of the quad cam arrangement.
You wouldn't want one to fail, went to a VX garage once to ask about a similar noise to yours, the mechanic asked me to shut it down there and then as he couldn't be held responsible if it failed in his presence so to speak.
I was a little bit unconvinced, it turned out one of the rollers had cracked and close to total failure . so there are some good mechanics out there in the main VX network, you just need to find the right one .

Harry

JohnL

Original Poster:

1,763 posts

272 months

Wednesday 12th February 2003
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Well just to update this one, they said that when they opened it all up again, one of the rollers was making a whole lot of noise that it hadn't been before they changed the belt!!!! Sound familar Harry?

They charged me for the labour again too, although restricted it to 2 hours compared to 3 before. Ouch, but at least that's sorted.

Incidentally for a set of rollers and tensioner, Vauxhall were going to charge them £240!!! But from an independent supplier it was "only" £74.

HarryW

15,276 posts

276 months

Wednesday 12th February 2003
quotequote all
Excellent, all's well that ends well then john, I can't remember the figures but the kit was no where near that expensive 3 years ago at the main dealer , I could drag out the receipt but I can't be ars*d, maybe they now see it as a good earner, fit the kit or loss your engine £5K please.
Here's to another 40k of omega cruising then

Harry

Captain Muppet

8,540 posts

272 months

Thursday 27th February 2003
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Failure mode for cam belt idlers: bearing grease degrades over time, bearing gets hot, heat degrades plastic wheel. Always change the idlers - they really should be a service item.
Some new idlers have more grease (aplication specific bearing rather than off the shelf items) and will last 150k+.