10 year old A-Class with a possible fault from the factory

Helmet Vonthrob

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So my partner bought her '99 A160 Elegance, with AC, in 2005 with 80K on it and a reasonable but not full history. Over the ensuing period I have done or had done most of the standard known stuff for the model; Coil pack, Power Steering Pump, Rear trailing arm bushes (both sides), Coil springs (x4). Just wish I had done a bit more research before she bought "the car of her dreams".

So about 18 months ago I started to hear a whine and when questioned she said it had been like that for "a while". Over the next few weeks the noise grew so I took it to a friend of mine, we couldn't see anything obvious, alternator etc. so put a new belt on which reduced but did not eliminate the noise.
About 2 months later I was driving on a long-ish run on a cold, wet day and by the end of a bit of a trash on the motorway, getting to a funeral, the note had changed. Subsequently the car cut out (fortunately when we were going home and AFTER the funeral. I got no warning but the battery was flat because the lower belt idler had collapsed.

I got the car recovered to my friend's workshop and a new part from GSF for around £15. I checked the belt (only a few months old) and it seemed to be ok. We took off the old idler and fitted the new one, re-fitted the belt and all was silent, cheap fix!!

Fast forward to about 3 weeks ago and she's reporting a budgie under the bonnet. Yup, there's a definite chirping but I suspected it was probably the alternator oh joy a £150 hit!

Back to my mate's last week, jacked the car up and had a quick once over, the 18 month old belt was a bit scuffed at the edge and all cracked when turned inside-out, I had bought another belt anyway so no big issue.

Nothing amiss with any of the other pulleys once the belt was off but we took the new-ish idler off just to check. He (not me) realised that there was a problem with the idler setup - we think the idler should have a deep dished washer either side of it for support as when we refitted a new belt it was running over the edge of the pulley (which may suggest why the old one had begun to fray).

Anyway, judiscious use of an 8mm captive nut in place of a deep dish washer had the belt running central again. Start up and no more budgie, result!

16-ish months ago when the initial idler failed we took the thing apart and I am convinced there was no washer there, we had to disassemble it to get the old idler off its pin and there was no washer. My mate is also meticulous and he wouldn't 'finish' a car if it meant leaving nuts, bolts, washers behind. So I am convinced even more that there was no washer/spacer there!

Could someone check on an exploded drawing if there is supposed to be a washer there.

So assuming that the idler hadn't been replaced before it collapsed the 1st time, I am minded to believe that the car left the factory without the inner washer.

Questions to more active and knowledgeable members than me;
Are idler failures common?
Is anyone aware of belt fraying as being an issue?
Have you checked your belt is running central??? - go on, you know you want to!!
 
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roofless

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how long do you expect parts to last :rolleyes: if the first idler was the factory fitted unit from 99 & had 80k on it in 05 when you got the car i would be thinking the new part is not of the same quality as the oe part or not fitted correctly
 

Xtractorfan

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Im not so sure that the idler pulley would also act as a guide for the belt run, the run of the belt would be dictated by the main drive/driven puleys, the idler pulley should be inline with the other pulleys, and only act as a tensioner for the belt...
 
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Helmet Vonthrob

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Im not so sure that the idler pulley would also act as a guide for the belt run, the run of the belt would be dictated by the main drive/driven puleys, the idler pulley should be inline with the other pulleys, and only act as a tensioner for the belt...

True, but the belt was not fully centred on the tensioner, due, I believe to a washer being missing. Therefore the belt edge (1-2mm) was overhanging.
 
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Helmet Vonthrob

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how long do you expect parts to last :rolleyes: if the first idler was the factory fitted unit from 99 & had 80k on it in 05 when you got the car i would be thinking the new part is not of the same quality as the oe part or not fitted correctly

Methinks you haven't read the post properly, the car has only suffered 1 idler failure the (presumably) factory fitted one.

And I have no expectation on idler life (other than the life of the car). I would be surprised if it is a consumable so wanted to get a feel for other people's experience.
 
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Helmet Vonthrob

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The link was for the idler pulley
 

jberks

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I'd doubt it was missing from the factory. They normally have very spcialised techniques to ensure things like that don't happen.
Whether it's supposed to be there in the firstplace I don't know (dealer or indie may if they've done a few) and where yours went is a mystery but if the puller was out of alignment from new, it would have eaten drive belts for a long time and chriped from new, plus straining the pulley would probably have caused a premature failure before now.
 
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