DST

Hi.

I have a 1999.5 A4 1.8TQ with about 95000 km. About two years ago, I had a number of front suspension arms go bad so I decided to take advantage of some of package pricing and have my mechanic replace all the front upper and lower control arms, the outer tie rod ends and the drop links. I also replaced my crappy all-season radials with Nokian performance summer tires.

Almost immediately, I noticed a rattle at the front-end that was noticeable after start-up, once the car was actually moving, and only for the first 3-5 minutes. Then it would go away and was usually not noticeable.

I posted on this about a year ago but I have new information now.

It has worsened over the last two years. I have had my mechanics look at it numerous times (they work on a lot of Audis) and they have not been able to locate it. At one point, we thought it was the plastic tray under the engine - we replaced the loose and worn fasteners and the noise continued. They replaced a worn inner tie rod end. The steering is now much more responsive but the noise continues. They have checked all the suspension links and the wheel bearings. For other reasons, I recently replaced three front end control arms. The noise continues. We have also checked the brakes for loose stuff, wheel-well liners, re-torqued the sub-frame and replaced some bolts on the front sway bars. The noise continues.

No one can explain it.

The noise has the following characteristics:

- Most noticeable at start-up and only once the car is actually moving;
- the noise is definitely at the front end and seems to be on both sides;
- the noise is not that loud but it is frequent, random and sounds like a somewhat metallic clicking/knocking;
- for the first little while, the frequency and randomness is a bit like corn popping;
- the noise subsides (and sometimes disappears) after 10-15 minutes of car movement;
- the noise is related to the outdoor temperature - on colder days, it is much less noticeable (in the winter, it was not noticeable at all) and subsides more quickly - on warm days, it is much more noticeable and takes longer to subside;
- the noise is not associated with the engine - engine operation without car movement does not produce the noise;
- the noise is not regular, rhythmic, grinding or rubbing noise as one might expect with noise associated wheel movement/rubbing brakes/bearings, etc.;
- not a creaking noise;
- doesn't really sound like control arm noise (believe me, I know what they sound like) and the pacing of the knock or clank seems inconsistent with control arm movement;
- the frequency of the knock or rattle does not seem necessarily to be produced by bumps or marked unevenness in the pavement (although it can be)- when I roll down my relatively smooth driveway in the morning, there is quite a racket from inside the car;
- car makes noise whether turning or going straight;
- noise unrelated to braking;
- I can ever so slightly feel the knock through the pedals (I may be imagining that):

Any assistance or ideas that anyone might have would be very very much appreciated.

I once was told that the strut mount bushings or shocks can sometimes produce this noise. Can anyone confirm that?

Thanks

David

Merkin

any play or leaks in the steering rack?

JAFO

check the front diff fluid level.

RKA

Are your shocks original (if not, at what mileage were they replaced)?

DST

yes

DST

the wheels when installing the control arms and they assure me that they do. Is that what you meant?

DST

boots are fine; front diff fluid checked in April

DST

also steering tight as a drum

audi49

My car consistently made a metallic rattling noise from somewhere in the front. The noise was quiet enough that i never heard it inside the car and it seemed somewhat intermittent. It didn't bother me. Based on reading these forums, I think I concluded that it was the oil pump but I never confirmed it. It sounded like a ball bearing rattling inside a tin can (although somewhat muffled).
When I got my timing belt service done about 1 year ago (timing belt, water pump, tensioner) it went away! So I don't think it was the oil pump. It was likely the water pump or the tensioner pulley, I'm guessing.
Maybe this helps?
Good luck.

RKA

check the shocks to make sure one of them isn't bad/blown