Hey, guys - I have this very strange problem and I'll try to give as many details as I can.

This problem takes place primarily only when the temperature is low, as in under 45F. The noise is this grumbling, very loud, grinding-like noise when the engine hits 1.0-1.2k RPM - the noise goes away when the engine is anything above 1.2k RPM and sounds perfectly normal. Even when coasting downhill, the noise is there as long as the engine is between 1.0-1.2k RPM. The noise never stops, regardless of how long the car has been running and even if the engine temperature reaches normal 5 minutes later.

Furthermore, the noise gets even worst when I'm steering the car, but this synergistic noise enhancement is only present at low RPMs, primarily between 1.0-1.2k RPM. Anything above 1.2k RPM, the steering does not exhibit any noise.

I've been doing some research in the issue, and a lot of people seem to have this problem and many of them point to issues with air getting into the P/S system. I'm starting to believe it is indeed a P/S issue because strangely enough, the noise isn't there for 10 seconds immediately after starting the car and only then does it start to lift its ugly face. Perhaps 10 seconds to take the bubbles to reach the P/S rack components to make this noise?

So first things first, I went ahead and took a peek at the P/S fluid level - it's above the max level. I don't think the Audi dealership technicians are idiots and overfilled it - but instead, I've read that there is a possibility that at colder temperatures, the fluid gets thicker and the P/S system is more prone to introducing air into the fluid by means of leaks/cracks in the hoses, reservoir, etc. So I turned the car on, did a couple of quick turns on the steering wheel, and looked at the P/S fluid indicator again. There were lots of bubbles in the liquid, which isn't good. So I believe the liquid is far above the max level simply because there's a TON of tiny little bubbles in the fluid, which makes the fluid assume a much larger volume and thus giving me a false reading.

So now here are my questions:

1) If the P/S system is faulty, then why would I hear the noise between 1.0-1.2k RPM even if I'm just going in a straight line and not even steering?
2) Why would there be noise only at colder temperatures - does that mean there wouldn't be bubbles/leaks in my P/S system when it's warmer?
3) What should I say to the dealership in order to best direct their efforts to remedying this problem?

A whole lot of words typed, but I'm hoping to get this issue fixed.

Thanks a lot, guys!
Kevin