Cambelt saga

[9-Points&Counting]

Hi all,

keeping a very long story short, does anybody know much about pulley wear or any other issue which could cause a cambelt to go two weeks after being replaced?

Basically, the belt went at 143k miles, technically wasn't due until 155k if you believe Audi, i had all the work done, then it went again two weeks later. The car is in the process of being repaired but I'm concerned there may be something else wrong which could've caused it, hence the question.

So could there be wear on the pulleys? Is there any guidance on when they should be checked, or that they should be replaced with a cambelt change after a certain mileage? Or is pulley wear unheard of up to a certain mileage on these cars?

FYI, the first belt had a load of teeth ripped off it, put down to old age, and I'm being told the second one has too.

Any info or help appreciated.
Cheers.

 

[s3dave]

did they change the tensioner?

 

[fingermouse]

seized water pump ???

 

[Welly]

Well, the second one certainly isn't down to age. End of.

To have the teeth ripped off requires some serious force. Much greater than something just slipping.

The tensioner pulley and idler pulley only ever see the back of the belt, so wear on those items 'shouldn't' cause this. Plus the idler pulley always comes in the cam belt kit, as does the tensioner pulley.

The most likely is tensioner damper failure, or a seized water pump. If it is either of these, they should be able to locate the problem and resolve.

When you say 'pulley wear' i assume you mean the sprocket on the cam and crank. I would be fall flat down on my **** surprised if there was ANY wear at all....

If there is no obvious cause for it, it may be something which requires more in-depth analysis.

 

[9-Points&Counting]

No seized water pump as far as I've been told. The first time was the belt getting teeth ripped off it because it was "old" and "overdue". Water pump was replaced, again as far as I was told, when the car was repaired. I'd be very surprised if a new pump seized after 2 weeks, but then I was VERY surprised anything went wrong after 2 weeks, so it can't be ruled out. Like I say, he's said it's a "belt failure".

s3dave - I was told they used a Continental kit which i think inc.'d the belt, tensioner and idler pulley, but not sure if the idler tensioner was done as well.

Thanks for the replies lads, i think this is worth discussing because i for one would like to know of any weaknesses in these engines and what else could go wrong with regards to the cambelt area. That's why I'm specifically interested in whether or not the cam and crankshaft pulleys could/should need replacing? I'm getting a bit nervous about this happening again and where that leaves me

I've been told my engine should be good for at least 200k, which fits with other stuff i've heard over the years about VW and Audi engines.

 

[Welly]

Cam and crank sprockets are VERY unlikely to be the problem.

The Contibelt kit does come with the belt, idler pulley and tensioner roller, BUT NOT the tensioner damper unless specifically asked for.

These engines are generally pretty good mate, this is the first time I've heard of anything like this I must admit.

 

[s3dave]

i had a car where the cam bearing had gone and ripped the teeth off the belt like you mentioned, maybe worthwhile checking all the bearings ?

 

[Welly]

i had a car where the cam bearing had gone and ripped the teeth off the belt like you mentioned, maybe worthwhile checking all the bearings ?

Cam bearing? WTF is a cam bearing?

'Throw me fricking bone here'. LOL

 

[s3dave]

http://www.youtube.com/watch?v=xbqN5wxMk0E

not sure if the 1.8t uses similar.......

 

[Welly]

Cam bearing? WTF is a cam bearing?

'Throw me fricking bone here'. LOL

Ahhh, bottom end. Fair enough, I was thinking camshaft seals to start with and it confused me as they clearly aren't bearings! :thumbsup:

Good find on the vid! lol.

 

[9-Points&Counting]

i had a car where the cam bearing had gone and ripped the teeth off the belt like you mentioned, maybe worthwhile checking all the bearings ?

So WTF is a cam bearing, if you excuse my ignorance, and would the garage need to check them while the head's off? (I can't watch the vid properly at work).

 

[Welly]

1.8T engines have cam bearings of a fashion - but not quite like the video.

http://www.audiforums.com/forum/showthread.php?p=1182336 will show you the equivalent on the 1.8t

Basically, these are the carriers in which the camshafts sit and rotate. If one packs in or breaks, it can cause the camshaft to be resistant to rotation, putting extra strain on the belt.

 

[9-Points&Counting]

OK. So if one or a few were worn out, would it be obvious to those that know and visible to the person repairing the head?

 

[Welly]

Yes, very much so.

I assume the head will have some bendy bendy valves, which means that the camshafts will have to come out, exposing the parts in question.

 

[9-Points&Counting]

Hi, sorry, been a bit busy with other things...

OK, this is getting worrying. So is this the type of thing that should be checked as well though, as part of the diagnosis, i.e. if it happens again the garage can't turn around and say "that's not part of the job", "it's not my responsibility to check them"?

Thanks for all your help by the way:thumbsup:

 

[9-Points&Counting]

Actually, is it also possible that the valves crashing into pistons the first time could've caused extra strain on the camshafts, which could've stressed the bearings to now cause teeth to ripped off a brand new belt?

 

[Welly]

Actually, is it also possible that the valves crashing into pistons the first time could've caused extra strain on the camshafts, which could've stressed the bearings to now cause teeth to ripped off a brand new belt?

Possible, but unlikely to have damaged the parts in question....

It would be their responsibility if they reassembled the head!

 

[9-Points&Counting]

OK, that's good to know..... thanks very much Welly, and thanks to everybody else for the help and info - much appreciated :thumbsup: