ajay_g

I have a 2006 A6 3.2 quattro sedan and over the last 6 months its developed this problem. When I start the engine it runs quite rough and loud (almost sounds like an old diesel engine). This doesn't happen every time I start the engine though. Initially I thought it was happening only when the engine was cold but recently it's started happening even when I've just driven it around and stopped for a few mins and started up again. The engine noise lasts only for about couple of mins and then it's back to operating normally. I've had it inspected by a dealer and they suspect something with the timing chains and have quoted me a whopping $6000 to fix it (and that's just the low side of the estimate) !!!! They also noticed some oil leaks coming from the gaskets but don't think that's related to this issue.

Here's a video of it:

At 1:03 you'll notice the sound changes
At 2:13 the sound returns to normal operation

I researched and found TSB-24-07-20 which talks about cold engine starts but I'm not sure if this is case with mine.

Please help ! I'm quite frustrated and am not sure I want to spend 6k-10k on a car which is worth only 10k. I'm no expert with the car so please bear with me if I use layman terms.

KevinGary

Sounds like the timing chain and tensioners. The dealer just replaced mine at 140k miles. As long as they were doing the chains I had them replace the torque converter as well since it was already out of the car.

ajay_g

Thanks Kevin for the reply. How much did you end up spending on it ? Just to get an idea if my quote is in the ball park or not.

KevinGary

It was $9900 including tax. The Tax would have been about $850 of that and the torque converter was about $1300 so the chains,tensioners and guides must have been $7700. I have the V8.

ajay_g

The thing I can't understand is if it's the timing chains related then shouldn't the noise be there all the time and not just go away after a couple of mins ? Also, if the engine is working just fine afterwards, I would think the timing chains are operating as they need to. Am I wrong in assuming that ?

KevinGary

Mine started making the noise at start up. When the check engine light came on the noise was constant.

ajay_g

Now that the weather has started warming up around here, the noise is happening on fewer occasions as opposed to almost every time in the winters. Did you notice this as well ?

Could this be related to oil pressure somehow ? In the winters since the temps are colder, the oil pressure is lower till it warms up ?? The dealer had noticed the timing chain covers were seeping. They'd also found oil leak from the right front vacuum pump which they'd recommended replacement. Could these be somehow related to this ? If these could be causing it then the fix is around $1000.

Still confused !!

4Driver4

If it was my car, I'd change both cam chain tensioners. Should cost you about 400 in parts. There is a good write up a few posts down.

Or you can drive until it fails.

6k is crazy money.

newa6er

They could be related, but I doubt it. You are correct in thinking that oil pressure is reason for more rattles in the winter, however, it's oil pressure in the chain tensioner and not the entire engine. I would not pay for any repairs on this car until the startup rattle is definitively diagnosed.

enoch861

Does anyone have a clip of how a normal functioning 3.2 should sound? Every video I see, the engine sounds different so I've never actually heard what a normal functioning 3.2 sounds like (with both the hood open and closed).
Mine doesn't sound like the video, but then I don't think it sounds as quiet as the video sounded toward the end. I did get my chains and tensioners replaced last year but I still don't think my engine sounds normal.. Maybe I'll post a clip of mine here and you guys can tell me.