Hi,

Ihave a 1998 A6 Quattro Avant 2,4 V6 (European spec) with an anoying metal scrambeling noise which starts a few seconds after start up, when the AC compressor clutch kicks in. Thenoise comes and goes with alterations in the workload on the serpentine belt. If I turn the steering wheel Ican provoke exacty the same noise, sometimes even when the compressor is turned of (in ECON mode). My dealer has replaced the AC fan, the AC compressor and some ballbearings connected to the serpentine belt, and the noise is still the same, loud and clear! I don't think I need to express my feelings about that in this forum...

Listen to the noise by clicking on the link underneath:

http://www.youtube.com/watch?v=Khe4rW_bXbY

If there are someone out there who can help I will be very very gratefull to hear your comments!

Sincerely

Thomas, Oslo Norway

 

how about the auxilary fan?

 

I'm not an Audi expert (I've onlyhad my a62.7T) for about a month - but I have been working on cars and boats for along time.

It sounds like it could be the water pump. If the water pump impellor let go/is letting go, it might sound like that.
you would also overheat most likely.

if you are not mechanically inclined - I would bring it to a mechanic quickly...

 

It's the smal fan on the left side in front of the enginethat has been replacedby the dealer (a well known source of noise on these cars). After thisthey replaced the compressor...The waterpump was replaced just over a year ago (red water leakedall over the parking lot) - I don't believe it has failed again. The timing belt was done together with the waterpump. The car has just rolled 129 000 km / 80 000 miles.

I personally believe that thenoisecomes fromsomelight metall -externally of the engine, not internally, because it issoclear andhigh inpitch. But, because it's so narrow and tight down there it's not possible to look or touch (when the engine is running...). The source is very low down - more to the right of flywheel. Just a thougt; could it be the tension of the serpentine belt, to much slack, that causes it to occasionally touch other metall parts down there? Or defecttensioner?

Is it easy to remove the cover underneath the engine (for a novice) to have a better look? I have access to a garage with a lifting jack.

 

its teh serpintine belt rollor, my old a4 had the same noise the minute i test drove it at the dealer but at 4k out the door i couldnt pass it up. i fixed mine by simplyly pulling it out and retensioning it but you may need a new one.