I have a 2009 Quattro 2.0T and have exactly the same issue. To me, it sounds like the fuel injector, it has that wet/hissing quality to it. It starts predictably at 2400 rpm.

I think it is the turbo, but not concerned as it seems everyone else is having the same issue. Also I would imagine if it was a problem, they will issue a recall

 

I took mine into the Audi dealership and took the shop foreman for a test drive. He said it's something rotational and I'll be bringing it back for a diagnostic check in a few days. When the car was stationary I put it into neutral and revved the engine, the sound wasn't there then. I'm certainly no mechanic but yes it must be something rotational in the drive shaft or transmission.

 

The problem was the left front wheel bearing. It was fixed under warranty and all is well.

 

TheQUad, thanks for posting back.

So your sounds (now fixed) only occurs when your engine RPMs are around 2500's? I very much want this to be "fixed" if it's fixable.. It' sjust funny to me that so many other people are having this exact same problem.. if it's a bearing problem..

 

The sound was noticeable around 2000 RPM and then more so with more speed. It was all speed related.

 

I'm almost positive that the noise is not a wheel bearing.

The Quad - what exactly do you mean the sound increased w/ more speed?

Related, try putting the DSG in sport mode and, atleast for my car, the noise isn't there. Do you guys experience the same thing (noise only when in 'D')?

How do we get Audi to pay attention to this problem before warranties are up and we have to pay for it?

 

Dsam09, I do not get that sound in S Mode.

I believe the reason is because S mode shifts when the rpm goes between 3000-4000 rpm. The sound only occurs between 2400-2600 rpm.. Not sure if this is why, but that's what I think anyways.

 

Nice information

 

The knocking sound was faster with more speed.

 

My 09 Quattro also had the noise. Brought it in to the dealer on Wednesday night for that problem and static in the rear speakers on acceleration. The service tech immediately identified it as a possible problem with the turbo wastegate. It is now Friday night and they are keeping the car until at least Monday. They said they had talked to the Tech Line numerous times, and they are having the dealership take apart the turbo and take pictures to send to tech line. I would not accept dealers telling you that it is a normal sound. They are obviously taking it seriously. I will re-post when I hear anything new.