A4 whirr/whine

[Fray Bentos]

I have a 2003 A4 Avant se (130) 6 speed (not Quattro) with 90,000 miles, recently a whirr or whine is coming from the front.
The noise has the following characteristics:
only audible > 30mph
Varies with Road speed
Does not vary with engine speed
Does not vary with gearbox speed
Does not change pitch or volume when brakes are applied
From trawling other forums I’m beginning to suspect differential bearings but would appreciate any advice.

[Huweth]

It could be the differential bearings, but I would guess you'd only have the noise when turning and not in a straight line.
Otherwise it is most probably a wheel bearing, or possible even a CV joint.
One way to check the bearings is to go for a good drive to warm them up. Sometimes, but not always, you can tell which bearing has failed because that wheel will be quite a bit hotter than the other due to increased friction. You can also try jacking the front up to see if there is any 'play' in the wheels when you try to wiggle them (pushing/pulling on the sides of the tyres, not trying to rotate them).

[Fray Bentos]

I should have added this additional information.

The noise does occur in a straight line - have not noticed any change when turning.
had the car checked by local garage and he confirmed the wheel bearings and CV joints appear to be normal without excessive play or binding

[farmer]

You haven't changed the tyres lately. Also some tyres start to create a lot of noise after they wear. If the bearings are ok, I would swap the front and the back wheels to rule them out.

[johno]

had the same trouble with my A4 Quattro turned out to be bearing on my car even though there was no play in it when checked hope this helps

johno

[Timk]

I have recently aquired a noise rather like this on my 1994 80 avant (150,000 miles).

It has occurred after (as a result of!) work on the front suspension and I suspect problems with the top mounts on the front suspension being overtight and transmitted increased road noise to the car.

The noise is quite bass-ey, almost as if its being enhanced by a sound board, and I even suspected a problem with vibration in the engine undertray.

I hope to get it solved next week one way or another!

Timk

[Huweth]

I suspect problems with the top mounts on the front suspension being overtight and transmitted increased road noise to the car.


Ah yes, I had this once too on a MK1 Golf. That could easily be the problem in the OP. With the top mount failure, the noise would come and go depending on the load on the suspension, i.e. over humpback bridges/rapid drops in the road the noise would go away due to reduced load.

[Fray Bentos]

from additional analysis of the sound (I'm becoming obsessed) I think it is likely a problem with the differential. Is there anyway I can verify this before taking the plunge and handing teh car 9plus I suspect a chunk of cash ) to the garage.

alternatively can anyone recommend an independent audi specialist in the York area who may be able to diagnose the problem without potentially replacing an unit that isnt faulty

many thanks