# are A6 (C5 generation) timing chains prone to premature failure?



## rret (Nov 15, 2004)

heard a rumor that the timing chains on this generation of A6's are prone to early failure - any thruth to that?


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## SouthboroAudiGuy (Jun 20, 2006)

*Re: are A6 (C5 generation) timing chains prone to premature failure? (rret)*

Pretty lousy rumor given the C5 engines don't have chains -- they have timing belts. 
That said, no, they don't fail more often than any other car (probably less) but the implications of a failure are dire due to the interference design of Audi engines (i.e., pistons and valves will make contact at high speed if the timing belt fails).
Final note: failures (when the do occur -- usually because somebody missed the service interval to replace the necessary parts) stem from a snapped belt ONLY a fraction of the time. Other parts that can fail are the tensioner or water pump (all part of the timing belt lineup). For this reason, people usually buy a kit that includes all of the necessary parts instead of just the belt.


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## rret (Nov 15, 2004)

*Re: are A6 (SouthboroAudiGuy)*

i'm asking this question for a friend of mine - don't know about the A6 engine. so while VW VR6 engines have chains, the A6 has belts? 
1) is that to make the engine quieter? 
2) do these belt(s) HAVE to be replaced at a certain mileage according to the owner's manual maintenance schedule?


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## SouthboroAudiGuy (Jun 20, 2006)

*Re: are A6 (rret)*

Don't know why belts are used (quieter sounds good -- could also be due to a complex path).
Recommended service interval on belts (follow the link in my sig to find a link to a maintenance schedule) varies between 90 and 105k depending on the engine & year. Most enthusiasts play it safe and get it done around 80k.


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## shweb (Jan 27, 2006)

*Re: are A6 (SouthboroAudiGuy)*

I've been having this conversation lately. Yes, the Bentley manual states (e.g., for the '03 A6 2.7T) to replace the TB and the tensioner at 105K. However, both my local indy shop AND the local Audi dealer recommend a TB replacement at 60K! The rationale is the climate (Colorado) with a combination of extreme cold, extreme heat and typically very dry air.
I'm coming up on 60K this spring. Although I might go as long as 65K, I won't go much further. And, at that time, will replace the tensioners (one is already leaking, but very little) and the WP with a metal imp.
Cheers.


_Modified by shweb at 3:48 PM 1-26-2007_


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## SouthboroAudiGuy (Jun 20, 2006)

*Re: are A6 (shweb)*

Consensus I've gotten from multiple forum is that 60-65k is WAAAY cautious. If you're OK with the clams necessary to do it, great, but I think you could easily go another 20k without problems. Audi has NO interest in recommending a service interval off by 75% -- and you can count on the fact that they take into account different climates.


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## shweb (Jan 27, 2006)

*Re: are A6 (SouthboroAudiGuy)*

Yeah, I hear ya. I certainly hadn't planned to do this so early. Yet, that's what came directly from the local dealer (Stammler in Boulder). His words exactly: "We're recommending that service at 60K." 
I guess I'd like to dig a little further and find out why a *dealer* is breaking so far from the official line. Any other feedback here?
Thanks.


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## SouthboroAudiGuy (Jun 20, 2006)

*Re: are A6 (shweb)*

Yeah. Find another dealer. I have a hard time believing they are not just trying to bilk you. Altitude/dry air may play a bit of a role, but a 30-40 reduction in parts life? I'm not buying it.


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## shweb (Jan 27, 2006)

*Re: are A6 (SouthboroAudiGuy)*

Well, I partially took your advice and contacted a different dealer in the area. He explained it in a bit more detail. It's not the TB that's the concern. They are also recommending a pretty major service interval at 60-65K, but it's for addressing the tensioners and WP. While there, they also replace thermostat and TB.
I am aware that the factory WP, with the plastic impellor, is prone to pre-mature failure, so I guess it makes some sense, then.
Maybe I'll go ahead and do it at 65K and replace the WP with an aftermarket metal imp. Then, shouldn't have to do another TB for another 90-95K after that.
Still, it's gonna hurt


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## SouthboroAudiGuy (Jun 20, 2006)

*Re: are A6 (shweb)*

Still not getting this. Why would YOUR water pump & tensioners need replacing before any other A6 2.7T owner's? It is common practice to do the water pump, tensioner, and TB at the same time. Also common that the belt outlasts the tensioner/pump. That said, people still routinely go to 80k without problems -- AND the recommended service interval is 90k+. Given the DIRE consequences of TB system failure, why would Audi recommend a service interval 50% beyond what makes sense?
I honestly think the dealer is trying to get at you wallet.


_Modified by SouthboroAudiGuy at 1:58 PM 1/29/2007_


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## shweb (Jan 27, 2006)

*Re: are A6 (SouthboroAudiGuy)*

Granted, the WP doesn't even show up on the Bentley maintenance schedule at all. Still two local dealers and an indy all "recommend" it all be done at 60K, not because of the TB, but because of the WP and it's silly to do that without going ahead and replacing the TB and tensioners while you're there. I'm not positive, but I think that makes sense.
Also, it's not just MY 2.7T. According to them, it's ANY.
I definitely hear your criticism, though, and I agree that it's a bit incongruous as well. Fortunately, I have plenty of time to think about it.
I was hoping to wait a bit longer and, when I do the TB, WP and all the other related stuff, move to the Stage III mtm setup. This spring will be a bit early for that (back to the wallet problem







).
Thanks again for your feedback.


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## fourpointwo (Sep 13, 2006)

I have a 4.2 with almost 80k and I haven't replaced my timing belts or tensors or water pumps, but im just about to do it.


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