So a month ago I'm driving along in rush hour traffic and I'm hearing a light clunking sound coming from the front end of my '07 A8 with 61,000 miles. It would happen when I would press the accelerator while going, say, 15 mph, and then again when I would let up off the accelerator as well. Almost as if something was loose as the drive train was engaging and disengaging. When at a full stop and the accelerator pressed, there would be no clunking sound. And while accelerating and shifting from one gear to the next, say on an on-ramp, no clunking sound. Everything seemed smooth as silk. It only seemed to be when the car would be stuck in the same gear, like moving slowly in heavy traffic without braking and letting the rpm's do the braking for me.

I'm not a car guy (as if you needed an explanation from my awesome description above), but it didn't sound right to me. So I take it in to Audi (where I bought it a few months back at 55,000 miles). I take a ride with the mechanic and replicate the problem. He says ok, let's take a look. They do their diagnostics and tell me that my transmission fluid was dirty and had metal flakes in it. Fair enough. So, per their recommendation, the transmission and drive train were replaced for $11k (I have a $200 deductible so no skin off my back really). Shipped from Germany so it took a month to do. Whatever. They say everything is perfect. I get the car back today and the same noise is there. Thoughts?

I'm going back in tomorrow to have another chat with them, but I figured maybe you guys had something up your sleeves on this one. I can't seem to find any other people with similar problems.

 

The only thing I ever saw that caused a clunk like that on an A8 was the front inner CV joints. Would think that would have been noticed when replacing the trans however. Had one we told the guy about (I'm was an Audi tech from '07-June this year) but he kept driving it and it came in on a flat bed with the joints disintegrated. CV joints are worth a second look anyways.

It is possible a worn/loose front suspension link could do it but most likely there'd be some sort of noise over bumps as well.

Remote possibility is a broken weld on the aluminum chassis/body structure. Highly unlikely,,,,,,,,,,,,,,but still possible.

Sorry I can't be more help. It is surprising the trans fluid had metal in it. As a rule, Audi transmission are bullet proof and last as long as the car (provided they aren't abused in some manner).

 

Thanks for the response, I'll relay it to the Audi tech. I baby this car 99% of the time, it's pure luxury and I want to keep it that way. The tech and salesperson said the same thing about the transmission being practically indestructible, as have others in the forums.

I'll update this post when I get more info. Don't want anybody else going through this same, albeit rare, problem.