Annoying "whine" noise in 2002 A4
 

About a year ago, my '02 A4 3.0Q developed an annoying whining noise that is noticeable when decelerating, like approaching a stop light or stop sign. The sound is not particularly loud, but can usually be heard over the radio and A/C blower. It changes pitch along with the speed of the car, and also happens when coasting to a stop in neutral. The car still drives well, except for some looseness/drifting in the steering (car does not track well over uneven or bumpy road surfaces).

I've had it to an independent shop and the dealer 4 times with no fix and am at my wit's end. The latest diagnosis from the dealer is that part of the transmission needs to be replaced, for the hefty cost of $5000. I can't believe this would be the case for a car with only 53,000 miles on it.

I think it is something to do with the servotronic steering or the pump, as one post suggested on here. The PS fluid looks to me to be brown, and has an unpleasant smell compared to new fluid.

Anyone have any experience with this problem?

Thanks

Some things to check on the '02s...
 

53k miles is pretty low for a trans. I'd look other places before thinking of ways to scratch up $5k.

Your control arms are probably shot- from what you explain of the bumper roads. Probably a clunk or 2. But that's not where the whine is coming from.

Check the engine and trans mounts. If they are crapped, then you'll get more engine/trans noise. Since it's speed dependent, then look at the trans.

If all else fails and you need a trans, you can get one rebuilt or a used replacement. BTDT.

Does the noise follow the accelerator, or only the car speed?
 

When anyone says "whining" I automatically think of the accessory belt tensioner.

Re: Does the noise follow the accelerator, or only the car speed?
 

I usually hear it when slowing to a stop -- foot off the accelerator and coasting/braking. Even when slowing from speeds of ~45 mph. It gets much more pronounced after the car is fully warmed up.

Sometimes can hear it faintly on the highway, too, but it is probably masked by road and wind noise. I don't usually hear it when accelerating, but then again, maybe the engine noise is just covering it up?

If it happens in neutral, it's probably not the transmission, since you are removing the load
 

from the engine.

Have you tried another set of wheels/tires if they are available to you? My old Kumhos got louder to the point of sounding like a helicopter.

I think the looseness of the steering is separate from any drivetrain whining, unless the whining changes when you go from lock to lock.

Mine makes the same noise
 

The noise was really pronounced when I turned the steering wheel at low speeds. So I checked the power steering fluid and it was low, so I added some. It didn't fix the problem.

Well, one day last winter I had to bring the car to the dealership for an unrelated repair, and I mentioned the noise from what I thought was from the power-steering pump to the service tech. He said they would check it out. When I got the car back, the noise was gone. They never told me what the noise was from, and they didn't charge me for fixing anything related to it, so I just took my car and went home.

Now, this winter, my car is doing the same thing. When the car is cold it doesn't make any whining noise, but when it warms up (especially on cold days) the whining returns.

The noise seems to be related to my steering, because I can hear the noise most when I am turning the wheel.
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did the check the center bearing on the driveshaft?

Re-read your question; yes, it only follows the car speed

Bunky did you ever find the culprit? Same problem here..
 

The car will run great for 5-10 minutes into the commute then will start making the noise from the passenger front most noteably between 20-40mph (and above, but masked mostly by road noise) once it is warm. I think I have ruled out the wheel bearing since when I turn side to side quickly I don't hear any difference in the sound. The only recent work I have had done in the area, was had the control arms changed out about 1,000 miles ago and had the tires rotated a couple hundred miles ago. Any other ideas?

04 A4 Q 3.0 USP
73,000

Thanks

No...
 

I'm not sure what to do with it. Noise is still there, and dealer claims its the center differential which needs to be replaced.

Did you ever have a combination of new and used tires on the car? I was wondering if new tires in front and worn in back could have caused the problem somehow.

Also, anyone know if the fluid in the center diff is separate from the fluid in the automatic trans? I've never had the trans fluid changed in this car.