My 95 A6Q has just developed an annoying rattle inside (behind) the front center grilles of the auto climate control. Heater works just fine.. indeed the entire control system is AOK... just this fan rattle.
It sounds like something is spinning and loose. Does anybody have a diagram of the guts of the fan housing
(Bently pic or such), or any ideas what might be going south?

Any help much appreciated.

AVUSgreg

Does the sound change with the fan speed?

The fans get noisy before they die. Mine had an intermitent squeal before I replaced it.

Is it a rattle or a clicking? Sounds like you've isolated it, but my first thought would be the compressor going....

Yep.. that's the culprit I think. The fan "sound" seems to start once the unit is up to temperature
(say 75 degrees). It seems to vary its sound when I turn a corner or come to a stop... Very unusual behavior. Does anyone know if the fan assembly is on some kind of gimball?

TIA
AVUSgreg

It is more like a "pinging" sound... as if something was hitting the tines in the fan assembly -- sort of like the sound generated when you put playing cards in the spokes of a bike... only higher pitched.

I don't think its the compressor.. AC works just fine and so does the heater.

TIA
AVUSgreg

Hello. I own a 1996 A4 2.8 quattro, purchased the car new in 1996 and I am aware of every noise my car makes but this one is new. While driving 3 days ago I heard a noise that sounded like a loose fan with a wheezing sound coming from behind my glove compartment. As I increased the speed of the heat the noise increased, when I decreased the speed I could hear a fan slowing down but the wheezing was still present but not as loud and obvious. The first day I noticed the problem I shut the heat off and went to restart but nothing came out of the vents. I shut the heat off again, I could hear the shut off click made and tried to restart. After a few seconds heat came out of the vents again, fist a bit cool and then warm. Even though I kept the heat blowing at a steady level in an almost high speed, the air blowing out of the vents decreases and increases from time to time on its own as if it is having a hard time to push out the vents or the fan is slowing and increasing speed on its own. There have been a few times where everything worked right, but it is guaranteed to start again. I checked the fuse but it looked fine. While the sound was present I stuck my hand behind the glove compartment and touched this black piece that looks like as if you are looking a car speaker from the reverse side, I felt a vibration of some sort coming from within it. Is this where the climate control motor fan is located? I must tell you that my climate control panel's digital screen has been inop for over a year maybe even two years, the lighted numbers and signs come on and go but most of the time they are off. I think this is a problem with all A4's. Has anyone had a similar experience with this type of noise? What does all this mean?