Timing belt came off a week after being replaced

[Dimebag]

So i recently had my timing belt changed on my Audi 100 2.5 AAT
Then after driving it for a little over a week one day it just stopped. During acceleration it made a weird thump and was dead. Opened the hood and peeked behind the timing belt cover and i could see the belt was off.

Got her towed to the shop that changed the timing belt and the guy who fixed it said he would look at it first thing Monday. As I'm leaving i see him opening the hood and looking very briefly at it before walking back in. I drove by the shop later that night and the car was gone so i guess he suddenly had time to look at it after all.

So i stop by today with my dad and ask about the car. What he told me was that a rock had cut the alternator belt. And that belt had got in between the timing belt causing it to come off. And that he took no responsibility for the damage

Is this likely to happen at all? Sound really fishy to me

[djh]

the timing belts behind covers as far as I know so doubt it, he's just trying to get out of having to sort it.

[Thuppu]

Seems that you have same kind of invertebrate shops and mechanics that we have here in Finland. Not everyone of course but unfortunately there is too much of these who can't do the job right and takes no responsibility of the work they do.

[spink]

hmm, unlikely,the timing belt on these engines are well shielded.Do you know if the vibration damper was replaced?its now common for those to split into 2 pieces which makes part of the damper smash into the covers and basically melt away the idler pulley/belt.I had it happen to mine a few weeks ago,luckily i was doing about 1mph at the time so heard/smelt things going wrong.I would go and ask for all the damaged pieces off the engine,that way you can probably find out how it happened.I think it is more likely the tensioner came loose or the bottom bolt wasn't tightened enough(large amounts of NM are needed to do the job properly).

lots of good info on the aat/ael on here

http://www.audifans.net/forum-3.html

[Dimebag]

Can't really prove him wrong either. He's a mechanic and that's the way it happened according to him.
Ive got the receipts from the time the previous owner's timing belt came off and that cost £3,809

[spink]

Can't really prove him wrong either. He's a mechanic and that's the way it happened according to him.
Ive got the receipts from the time the previous owner's timing belt came off and that cost £3,809

how much are those cars worth in norway out of interest?i can quite imagine £6000 or more

[UrS4boy]

C4 S4 S6 Serpentine belt replacement DIY

...So i stop by today with my dad and ask about the car. What he told me was that a rock had cut the alternator belt. And that belt had got in between the timing belt causing it to come off. And that he took no responsibility for the damage. Is this likely to happen at all? Sound really fishy to me

The story smells. That said, with the AAN 20 valve turbo I-5 engine in the C4 100 S4s and S6s, it is possible for the serpentine belt to break and shreads of it to get caught up in the crank to cam timing belt and break the belt. This has happened several times to various people and they are always surprised that it is possible given the cam timing belt is behind a cover. It is, except at the very bottom at the crank pulley.

This is one reason why I wrote up this serpentine belt replacement DIY:

http://forums.quattroworld.com/s4s6/msgs/22579.phtml

[Error404]

sounds like ******** to me, is they are anything like the I5 petrols there are two parts to the timing belt cover to prevent this from happening.
As above, lets see the idler and crank sprocket

[Dimebag]

how much are those cars worth in norway out of interest?i can quite imagine £6000 or more

You can get a good one for about £5600

[s2_bo]

I don't buy it at all. Sounds fishy. Ask to see everything, Inc the rock that did the damage then post pictures on here and we can tell you what really happend.

Did you pay for the work by credit card? Of so contact your card card company and warn them that you may need to reverse charges on the payment due to a ****up on the garages part.

[mcandmar]

All sounds very unlikely to me. My first suspicion would be a failed crank pulley for the timing belt, either not replaced or torqued properly, possibly both. Without seeing the bits its impossible to say really.

[S2central.net]

Rule #1 for such a situation - should have gone to independent garage or engineer report on root cause before going back to garage that done the work. Sadly i feel you gave him free reign to wriggle, dodge and ******** you with a very unlikely story. Way too much of a coincidence on that **** and bull rock story.

I have seen stones ingested by unprotected belt on a rally car that caused failure of tensioner but with covers on it is very unlikely.

[spink]

I was looking earlier today at a AAT pulley and it is a different design to what is on an AAN,where the pulley joins to the crank sprocket is much better protected from a aux belt getting sucked into the cambelt zone,i didnt get a pic of it but you will realise when i put one up

Whether the rock or the mechanic takes the blame for this you must make sure that a good vibration damper is fitted,mine failed at 220,000 miles(14 years old),i started working on another today of the same age which has done less than 100.000 miles an exactly the same thing had happened to that

those cracks in the rubber are the beginnings of disaster

[UrS4boy]

I was looking earlier today at a AAT pulley and it is a different design to what is on an AAN,where the pulley joins to the crank sprocket is much better protected from a aux belt getting sucked into the cambelt zone,i didnt get a pic of it but you will realise when i put one up.

Here is the diagram showing the AAN/ABY/ADU covers. As can be seen (I think), the crank pulley is not completely protected, i.e. the opening at the bottom of Item 5, the lower toothed belt cover. This "chink" in the "armour" (acceptable word in this context) leaves the 20vT open to issues, including cam belt breakage due to debris (including serpentine belt shreds). How this relates to the AAT, I don't know.

[Phil Payne]

hmm, unlikely,the timing belt on these engines are well shielded.

Almost every photograph I see of a 20V conversion into an ur-quattro has no upper cam belt cover in place.

Sends shivers down my spine.