Mike141

My 05 is just about 75k and I know Audi recommends change at 75k and this was switched from like 90k originally. Just asking if anyone has had any timing belt failure prior to a change. I am getting it done pretty soon just don't want to have it snap. Thanks

Brozee

There are soooo many threads on this it really isn't worth repeating, but to answer your question I haven't heard of any on an D3 A8 breaking but I for sure as hell wouldn't change it at 75k. Check the condition of the belt and change it around 100k depending on the condition. 75k is overkill, unless it is old (7+ years). Just changed the timing belt on my girlfriends v6 sebring (really a Mitsubishi; thank god!!!) and the timing belt was toast at 142k, previous owner didnt do anything. It was like a belt you wear, no ribbing left. But the audi belt just inspect and don't worry about the schedules, they do it for money!! Change plugs every 50k, air filters every so often as well as cabin air filter and your all good. That is all.

MP4.2+6.0

you look at higher volume apps of same basic motor--C5 and C6 A6 4.2, C5 S6, S4 w/ the 4.2, Q7 or Tuoureg w/ 4.2, plus the D2 A8 and S8 4.2. Can just search archives generally. You'll find a few, but not particularly known for it statistically AFAIK. Very bad news if it happens though.

You may find a more prevalent issue is the thermostat, which causes digging deep into the same area of the motor anyway.

A8nightmare

I changed mine at 60K because we were doing some other work on it. You will have a failure in something else before the belt ever goes out. I have not heard of any of them breaking. Hold off until at least 100K+, then get the Blau parts kit and do everything.

Mike141

Ok when inspecting it, what exactly am I looking at to make sure it's still good? Make sure the ridges are sharp underneath? and obviously make sure no splits, right? Just new at this, all my other cars had timing chains, never had to deal with this. Thanks!

A8nightmare

You can check the ridges, but they will be fine. The belt cannot come off the cam sprockets or slip anyways. Note the belt will have a lot of slack appearing extremely loose when you take off the cam sprocket cover on the left side. That is normal it is just the way it ends up when the engines off. Don;t worry about any of it till 100k+, but if you are doing it yourself and need any help let me know.

Brozee

The belt if it needs to be replaced will just be cracking, or be dried out.

MP4.2+6.0

as or more likely than some fluke where the belt alone tears apart is the risk of a belt tensioner or water pump failure that then secondarily can lead to belt failure. If the water pump locks up or the tensioner craps out badly, the belt will either break/burn through, or could slip teeth/fall off as a consequence. There are also a few idler pulleys w/ bearings that could lock up too, but seemingly less likely from prior 2.8 and 4.2 general experience inspecting and changing the parts involved. All this stuff (plus the thermostat) is changed out in a comprehensive timing belt job. Still, per my prior post pretty well engineered and proven, so this is really how much insurance you want to buy, and when, against what would likely ruin the motor. To me the outer end would be when the risk of water pump or thermostat issues get to be material.

Edd W

I have only ever seen a belt fail due to oil contamination or mechanical failure.
The greatest risk to leaving the belt change too long is not the belt itself, it is the idler and tensioner system which is most likely to fail - providing there are engine oil leaks at the front which are allowing any oil onto the belt.

SimonBackman

I've literally JUST changed my belt within the past 5,000 miles. I did it around 110,000 miles and I was told the belt was DONE. We're friends with the service manager at the local Audi dealer so we got body shop prices for parts and paid the technician under the table to use audis equipment, let's just say we got it cheap. Anyway, the car feels amazing, it's like I got 20-30 horsepower back and it just feels so fresh. I would recommend you shop around for prices because I think the dealer will quote you around $1,500-2,000.