Help! Astra whining after cam belt chang - bazza
Could do with some advice please from you experts out there.
I had the cam belt and tensioner/pulleys changed about 3 weeks ago on my Astra 1.6 16v 99 reg, 41000 miles. Ever since, there has been a constant pronounced whine from the belt area. Left it a while as I thought it might "bed in" and disappear (always the optimist!) but finally took it back today. The garage (which by the way is entirely reputable but not main dealer)listened to it and their diagnosis is that the cam belt cannot be over-tightened as the belt tension is governed by the tensioner itself.They think the whine is the alternator bearing and as a new oneis about £200, not worth doing anything about it just yet. I'm not convinced as the noise only began immediately after the new belt was fitted. So what's going on? Could it be an over-tight drivebelt putting more stress on the alternator bearing or what? I don't know what to do next apart from take it to a GM garage for a second opinion. Does anyone have any experience of this type of problem and/or advice on what to do next? I need the car to be reliable for long commuting and driving abroad.


Help! Astra whining after cam belt chang - steve paterson
Don't know about your engine, but normally it's easy enough to remove the alternator belt and see (hear) if the noise is still there. A cheap stethoscope can pinpoint elusive bearing noises.
Help! Astra whining after cam belt chang - Dynamic Dave
I would say it is the cambelt thats whining.
If the cambelt tensioner is similar to that of the Cavalier, then the belt can indeed be overtightened. You have to adjust the tensioner initially by making sure the indicator pointer on the tensioner aligns with the centre of the baseplate notch. Thereafter the belt will self tension.
Does the noise increase once the engine is warm?
Help! Astra whining after cam belt chang - bazza
Thx, Yes I think it's the belt whining too. The question is - is it safe to live with it and/or will it slacken off in a few thousand miles ( ie will the belt "give" slightly) or will an overtight belt place undue stresses on bearings etc, suggesting early remedial work?

SP - thx for the tip, I'll do that as soon as it warms up a bit outside!! I'll use my old trick of listening through a piece of overflow pipe, used as a stethoscope!


Help! Astra whining after cam belt chang - Dynamic Dave

Personally I would get the tension rechecked. A cambelt doesn't have a lot of give in it, unlike a fan belt. It's normally fitted and forgotten about until the next change. As you suggest, it could put undue stresses on other components, such as the tensioner.
Help! Astra whining after cam belt chang - bazza
Thanks DD, advice much appreciated.
Help! Astra whining after cam belt chang - M.M

This noise could be very serious to your pocket.

It is quite possible the garage overtightened the alternator belt which would have gone back on at the end of the job. If so make them take it off to prove the timing belt/pulleys are quiet, then get them to fit the alt' belt properly.

If it is noisy with the alt belt off I'd stop using the car until the garage had resolved it.

As DD says the tensioner does float and apply the last part of the tension with a spring BUT it is possible to get this setup wrong so the belt is much too tight...and that is usually the cause of noise after a belt change.

I'm sure the procedure involves setting the tensioner to two different positions and turning the engine over 4 times before the final set tension range is achieved. Room for a mistake I guess?

Did you have a new tensioner/idler set??

Help! Astra whining after cam belt chang - Dynamic Dave

If the alternator belt on the Astra is of the same set up as the Cavalier, then this belt also has a self tensioner, but unlike the cambelt, it is non adjustable. You just apply a big spanner onto the bolt that is holding the pulley onto the sprung loaded bracket, pull back on the spring to slacken the belt and remove. When you refit, pull back on the spring again, put the belt on and let go.
Help! Astra whining after cam belt chang - M.M

Re Alt belt self-tensioner?

I haven't done a timing belt on any Astra later than early '98 so wasn't sure about this '99 model, that older one did have the self tensioner which is possibly fitted to all models with a ribbed belt.

But my point still stands, that alt belt needs to be removed to see if, for whatever reason, it is the alt or belt making this noise given the possible cost if something is badly wrong in the timing belt area.

Ian makes a good point about tooth profiles. Just once I've been supplied with a belt that was the right width/length but had square rather than round teeth...or vice versa.

Help! Astra whining after cam belt chang - kithmo
I suspect the cambelt has been overtightened. On the 1.6 16v Mk4 Astra the timing belt tensioner pointer (as mentioned by Dynamic dave) MUST be aligned with the centre of the notch if it is a new belt and with the edge of the notch if replacing a used belt. They can over tighten it if they aligned it with the edge (used belt position) instead of the centre.
Help! Astra whining after cam belt chang - Ian Cook
In addition to the excellent advice given here, I'd also check that the garage has fitted the correct belt.

I don't know of anything specific to Vauxhalls but I knew of a bloke who'd had just the same problem as yours and it transpired that it was the wrong belt, with a slightly different tooth profile.

Ian Cook
Help! Astra whining after cam belt chang - bazza
Thanks everybody - great response, it's so useful having access to all this unbiased knowledge! On the basis of all your valuable advice I drove gently down to my local GM dealer this morn and had a chat with their service manager. He believes the belt is too tight as well, so I've left it there, hopefully they'll have a look today. I'll post an update.
Help! Astra whining after cam belt chang - Dynamic Dave
hopefully they'll have a look today.

Shouldn't take them long to verify if too tight or not. Undo cover at the top, pull back and peer down inside with a torch to see what mark the adjuster is pointing to.

I spoke to my mate who used to work for Vauxhall this morning, and he said the same thing - too tight. However he was taught to air on the side of "slightly" tight on the adjuster to allow for the belt stretching over the 36,000 (now 40,000) miles before the next belt change. But if the belt whined when fitted like this, move the adjuster back to the specified pointer marks.
Astra whining update - bazza
Folks, here's the outcome of it all:-
Just got the car back after 10 days waiting for a part! The cam belt was too tight, and apparently the wrong tensioner was fitted. The original factory-fitted one is made of metal with Opel Canada stamped on it. The one fitted by my "independant" is made of black plastic, believe it or not, with VKM stamped on it. The bearing part is SKF France. Also the poly V belt tensioning bracket was hacked up with the wrong bolt and stripped thread, hence the wait.
Anyway, I'm severely out of pocket here and was wondering if I hasve any come-back against the original garage. They have always been OK in the past. I'll be doing things myself like I used to from now on, I only took it there for convenience as it looked like a hell of a job!

Thank you very much for all your help everyone.

Astra whining update - M.M

I would politely be asking the first garage to refund all costs of the timing belt job they did.

You gave them the opportunity to look at it and they came up with the stupid idea that it was alternator bearings.

If they had half a clue about these engines and their potential to snap/jump a belt they would have been much more interested in tracking down that noise.

After all if you hadn't taken it back to them and then persisted with the second garage who found these problems then they could be facing a bill for nearly £1K had the think failed on you.

I would be deeply embarrased and give you an on the spot refund.

Astra whining update - Dynamic Dave
It just goes to show it's not always "better the devil you know" where garages are concerned. All garages tend to have a black sheep mechanic that does a bodge job; looks like it was your turn to suffer his workmanship.
I would politely go back and point out their error, with any evidence you have from the garage that corrected their cockup. If no joy then either you walk away out of pocket and vow never to use them again, or seek some kind of legal advice. Personally I would seek the legal advice. Somewhere like the CAB would be a place to start.

Glad you got it sorted in the end though. Hope all goes well with gettign your money back from the rogue garage. Keep us posted.
Astra whining update - blank
That is apalling. I, like the others and I expect you, am glad you kept pushing and got a second opinion.

I would suggest doing your best to keep calm, see the boss and follow the advice given by Dave and MM.

Good luck
Astra whining update - Dudley
A fascinating story - mirrors my noise having had a replacement belt to my Rover 218 diesel. The garage (usually very fair independent bunch) listened to the noise and pronounced it "a rattle in the plastic somewhere that customers often complain about after we've worked on a car".

I actually re-adjusted the alternator belt just after they did the work because I, too, was concerned they'd simply tightened it too much, But the whine continues.

anybody know whether my problem is the same as bazza's and it's simply wrong parts fitted? If ther's any suggestion of this, then in view of the dangerously expensive consequences of a foul up on the timing belt scene, I'll take action for sure!


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