I have an '03 3.0 and am experiencing the same issue. However, mine does it when it's around 65 or under, at 40 it's really loud. The resoivor is full of bubbles when it starts. I'm not experencing a decline in steering performance, no jumping or anything that I've heard comes from a bad rack. My fluid level is good and there are no leaks. I also experience a similar sound when de-accelerating at 40mph and under even if I'm not turning the wheel. The sound only happens when it's under 65 (goes hand in hand with the power steering groan) or if it's above 65 it does it when the A/C is on. I've taken it to 4 shops and no one can tell me anything except that everything looks good. I had a certified Audi shop tell me it's my A/C but why would my power steering be loud and be getting bubbles if it was the A/C? It also idles rough from time to time but only when I'm in gear, they also blamed the A/C for it even though it does it A/C on or off. Could they be right??? I'm very hesitant to drop the money on fixing the A/C and it not fix any of the noise issues I'm having. Also, when it does that sound on de-acceleration I can sometimes fill a vibration in my steering wheel along with the sound, I've done a ton of research and can't find a single person experiencing this.

 

Your belt probably??

 

Bad belt would not induce bubbles into the PS resivoir. Sounds like a leak int eh PS system somewhere and you've got a bit of air getting in. The air is probably getting in and as it passes through the system your pump gets noisy.

 

The belt is brand new, only has about 300 miles on it, the sound is no different then it was before the belt was changed. They also said one of the tensioners was bad and replaced that. As far as air getting into my pump...would that cause the noise I'm experiencing at 40mph and under even when not turning the wheel? Also, I noticed yesterday that if I'm sitting at a light and my idle is rough and I turn the wheel the idle will become more rough and my RPM's will bounce up and down a bit with the wheel. This only happens when the pump is noisy which is only when it's about 65 and under outside. Also, if I drive more than a half hour it seems to almost completely go away as well.

 

I honestly don't know if air or no air would cause the symptoms you're experiencing, but I'm pretty certain that there shouldn't be any bubbles in your PS fluid and if there are bubbles in there, they're coming from air somewhere in the system. You've probably got either a leak in your system somewhere or an air bubble stuck somewhere. Either way it sounds like a PS system probably, not an air conditioner problem.

 

That's what I'm thinking too. I found a TSB that is supposed to address loud P/S pump and followed it exactly but it didn't help at all. It involved topping the fluid off and turning the wheel back and forth 15-20 times with the cap off to work the air out. I've done this three times now with no improvement what so ever. Is it possible for air to get in the system without there being a leak? I haven't lost a drop of fluid since this started which was several months ago.

 

I did a brief look at the power steering system this weekend and cracked/leaking hoses weren't obvious to me. I didn't spend a whole lot of time due to some other maintenance, but I'll try again this weekend.

I found 2 TSB's related to this problem that may be valuable:

• For the noisy power steering - TSB says air is being drawn into the power steering pump (surprise, surprise) in cold conditions. So the likely cause is a bad/cracked/loose line somewhere...let the hunt begin.
• For the low RPM whine - According to the TSB, it's a poorly lubricated roller bearing...either the idler roller bearing or the belt tensioning roller bearing.

Once i figure out how to lubricate these properly, I'll give it a go and see if there any improvement. It's starting to get cold here in Iowa and these noises don't improve with temperature...they get A LOT worse.