New member looking used A6's

[cbova]

Hello guys, new member here. I'll keep the intro short. I currently drive a 2010 VW Jetta TDi 6Spd with 150k on it. We are looking for something slightly bigger, auto, and AWD. We are looking at 2005-2007 with 115k-135k mile A6 3.2. I do all my own work from oil changes to total rebuilds. I'm not scared of normal maintenance (shocks, brakes, swaybar links, wheel bearings, CV axles, etc...) and I already have a VCDS for the VW (I'll have to upgrade for Audi but I'm familiar with the software). Aside from the normal used car issues my research has left me with a few questions.

My two major questions are;
1. how reliable is the automatic transmission? I need to get to 200k miles with the A6, with the auto do that with proper maintenance? Through my days of searching I have found very few issues regarding transmission.
2. How common is the timing chain tensioner failure? And when it does fail, how often does it cause valve damage? If caught early is it generally acceptable to change only the upper tensioners (both sides) with the engine in car?

I found 2 cars that currently have failed tensioners. For the right price is it worth it to buy and fix? The price has to be really good because there are many risks involved with buying a car that can't be verified.

Generally speaking will these cars go 200k with an auto.


Thanks,
Chris.

[SinCityA6]

With proper maintenance, I have heard of these cars going 200k plus. The transmission is a solid unit, again when properly maintained. As for the timing chains, they are the Achilles heal of the car. When they fail completely, timing skips, cylinders collide with valves and the motor is shot.
Unless you are willing and able to pull a motor, separate from the trans and replace all guides, chains and tensioners, then u would steer clear of the cars you reference. Who knows what internal damage has occurred because of the failure.
What is your budget? Can you get into a 2009 or newer with the 3.0 supercharged motor?


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[c@@kieMonsta]

Sin,

The timing chain isn't the achilles so much as the chain tensioners themselves are. And to replace those, it is not necessary to pull the engine out and can be done via DIY. Otherwise a chain failure is a lot less likely to happen compared to a belt failure - which results in the same catastrophic damage.

All that being said, OP if I were in the market for a very high mileage C6, I'd make sure that the maintenance record from the prior owner(s) was impeccable with no major work needing to be done in the past, otherwise you'd have a ticking time bomb on your hands if it was neglected.

[SinCityA6]

@ c@@kieMonsta - when I referred to the timing chains being the Achilles heal, I was referring to the whole set up (guides, tensioners, placement, etc.)
The majority of the time we hear an A6 having a catastrophic failure, it always comes down to those issues. That being said, I would rather have the chains over a belt any day.


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[c@@kieMonsta]

@ c@@kieMonsta - when I referred to the timing chains being the Achilles heal, I was referring to the whole set up (guides, tensioners, placement, etc.)
The majority of the time we hear an A6 having a catastrophic failure, it always comes down to those issues. That being said, I would rather have the chains over a belt any day.


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I think this guy sums it up best!

"As with all things, the chains and tensioners will wear out. But this should only occur on very very high mileage cars when maintained properly (regular maintenance, oil changes, etc). The chains and tensioners will fail prematurely if the car is ill maintained or beaten (driven) very hard. You will find many cars here that have well over 100k miles with nary a problem with the chains/tensioners; and you will find some (much fewer) that have. It should not be of concern if the car has been maintained well and driven reasonably."

[SinCityA6]

He sounds like a wise one, he does!


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[cbova]

Thanks. My budget is $8,000. It's going to have to be a damn good deal (3500-4k) for me to jump on a non running example. I have not looked at any yet but I want to get my ducks in a row before I do.

[cbova]

Well I opted out of the two cars listed on the original post and bought the wife a Volvo XC70 instead ('05, 100k mi). Fast forward a month and I ran across another A6 Avant, accidentally on purpose we'll say. It's 2006 higher mileage (160k) with blown engine, presumably bent valves in at least on head. The price was right ($1500) so I took the chance. I like the cars and like the project. Not my first overhaul by any means but certainly the most modern. This will either be a budget beater to keep some miles off my truck or flip it for some cash. Generally speaking when the timing system fails on these does it take out one head or both? I'm assuming it was only one in this case because the owner told me (I did not pick the car up yet) that the shop said it runs on 3 cylinders. If it is only one head, is it acceptable to replace damaged valves, lap them in and move on? Leaving the "good head" alone. Will the head need to be resurfaced, or are they generally OK to reuse as is? Do cams and variable timing components usually survive the catastrophe? For obvious reasons I don't want to dump a boat load of cash into it but seemed like a fun project/car if I can keep it reasonable. Right now, without even seeing the car yet I'm up to about $2200 in parts assuming all the valves on one side need to be replaced. Most of that is ALL of the chains/guides/tesnsioners (ECS). Used engines in my area are close to the 2k mark as it is and then I would want to do AT LEAST the upper tensioners... I will buy the service manual and have a VCDS.

So was it a stupid decision to take this on? If it get's to the point where it looks like it won't be economical hopefully I can part it out and re coup some of the money.

Thanks,
Chris

[jstarr427]

only problem with damaged valves, is that they can easily damage the valve guides as well. not to mention what they've done to the pistons/block can be nasty. I've seen an example on a MKIV Golf that required block repair. I need to find me one of those projects!

[cbova]

I'm hoping there's not too much damage to the bottom end. The seller told me over the phone that he was on a road trip, stopped for gas and it was "acting funny" so he had it towed to a shop. Shop said it runs on 3 cyl and that the "timing had jumped". Picking it up tomorrow, probably wont have time to dig into it for a few weeks.

[cbova]

nevermind, the douchebag sold the car out from under me.