A84Nate

I love the D2 platform A8 models and have been thinking of picking up a used one at a smashing good price. But I have reservations concerning reliability. Someone once told me that "if your Check Engine Light isn't on, you're not driving an Audi." My biggest concern is with the 4.2 V8 engine. I've read on various posts that the 4.2 is belt driven instead of chain driven...is this true? I used to work at an Audi dealer and heard many horror stories of timing-belts snapping long before the recommended service interval. I don't want this to happen nor do I want to pay to have it replaced at all. Could someone with first hand experience or reliable knowledge please answer this question as well as inform me of what else I should look out for. What are the other problem areas of the D2 A8? And what can I expect for regular maintenance over the long term? I'm looking at MY 2001-2003 with less than 80,000 miles. Please help! I've never owned an Audi before.

silverd2

The belt thing is more of an "If" paranoia thing in my opinion. If it breaks, you'll destroy a bunch of valves. If a satellite falls on you, it'll probably kill ya.

I've owned countless VW's, all belt driven...never a belt failure at any mileage...let one go 140K and it was still supple, no broken teeth. 3 Porsche 928's ($80K + cars), all belt driven....never any damage to old belt when changed at any mileage. Just changed the belt myself on my '01 A8 at 100K miles...old belt near perfect, supple, no damage, every tooth good.

I've heard of it (without knowing all factors) but, I've personally never known anyone to have a belt fail, especially prematurely. Most of the stories I've heard in good detail (on good German cars) about belt failure were caused by failure by a mechanic to tension properly, misalgned, failure of tensioners/rollers or belts at astronomical mileage, that could have been caught easily by simple occasional inspections. Other than one time, getting "whining" from a roller in a VW, which I changed, I've never had any part in a belt system (belt, roller or tensioner) actually fail, even at above recommended mileage.

These belts are not constructed like your old fashioned generator belt in a VW bug. There are even some pretty exotic motorcycles that use similar belts to drive the rear wheel, instead of shaft or chain drive. Any part can fail, especially if neglected.

Incidentally, I understand that some extreme weather conditions (desert, etc..) can effect the life of these belts(?)...don't know...relatively humid most of the year where I live.

I know there are other stories out there, but I personally have never heard of a belt failure (simply because of the belt) in a 4.2 A8 engine...but I haven't really looked for such a story. I have had expensive bicycle chains break on custom bikes, just from my own leg power, though.

This link gives you some good basics on A8 care:

http://www.audiforums.com/forum/showthread.php?t=112161

Recent threads on this forum have touched on A8 maintenance in general too...here's one:

https://www.audiworld.com/forums/sho...2786909&page=2

Remember, a lot of maintenance problems discussed are worst case scenarios and some ARE common problems...there's thousands of these cars out there and you're just reading about a few of them. All cars, at any price, have their sore spots.

80K miles is LOW miles for an A8. Upcoming recommended maintenance, like timing belt change (for instance), even if you don't do any of your own work, can be done at a fraction of the price by good mechanics, other than a dealer... just shop a little. I NEVER buy parts from or let dealers touch my car unless it's something simple I just don't have the tools for and can't find elsewhere.

silverd2

P.S.
As for the CEL (check engine light), depends on what state you live in (inspection).
It can be triggered by hundreds of things in any car.
Fortunately my state does not do inspections. I've had a CEL on in mine for a year, which is for something so insignificant, it's not worth the expense or trouble of addressing and realistically affects nothing.
A cheap code scanner (reader) can tell why it's on...or any mechanic with a scanner.
If it's on in a car you're gonna buy, I'd have somebody stick a scanner in it (everybody's got one), esp if you live in an "inspection" state.

A84Nate

Thanks silverd2, your posts were exactly what I was hoping for. Very helpful!

ltooz_a6_a8_q7

I've never had a check engine light on in 6 years. I have not had any major work done or little thing done in 5 years until 150k miles. Look at my website on A8. It's the most reliable car ever, even beat any Japanese car.

Cheers and good luck,

Louis

silverd2

Louis,

In TN, the check engine light is just something that helps you see the speedometer at night

...no state income tax either.

A84Nate

I have a question regarding the 4.2 V8. This engine is used in the A8 and B6 S4. But in the S4 the engine is flipped backwards and is chain driven. Why?