Arne Bjarne

Hello Audiworld!
I recently purchased an A6 99' 2,4l Quattro. It runs real great, and I have had no big issues so far (knock on wood).. (except for the washerfluid pissing right out when i refill..Hopefully its the hose and not the tank..)
However, there is some sort of "spooling" noise coming from the head unit somewhere, right about behind Aircon control. I thought it would be the fan or something, but the sound is there, even when the Aircon is switched off..Im not really sure how to explain the sound, other than it sounds abit like when you switch the master switch on in an airplane..Like..electric spooling of that makes sense..
It is not very loud, and no big deal, just annoying when everything else seems to be in perfect condition.
Anyone got any clue what it might be, and/or what I can do to fix it?

georgeb944

If you have secondary air injection on that engine, most likely the air pump. The bearings are going bad and it makes a sound like a dentist drill. Should only happen when starting up the car in the morning.

Arne Bjarne

The air pump, ok. Will it have to be replaced, or is it ok to leave it? The sound was still there after 30-40min driving this afternoon.

georgeb944

If you disconnect the plug to the pump, you will avoid blowing the 40 amp fuse, which is a PITA to replace.