Noise when using Climate Control?

[Guffbert]

I am in need of some advice please... I own a 2008 A3 Sportback S-Line. Recently I have noticed when using the climate control, there is a whining noise. I have noticed that the noise changes tone slightly when the engine is revved. It definitely seems as if the noise is coming from behind the dash?
I have also noticed that if i press the Econ button the noise disappears. I was just wondering if anyone else has had this problem, or if they know of any fixes for the noise.
I bought the car just over a year ago, I don't know when the Air-Con was re-gassed, but not having much experience with Air-Con, I don't know if low gasses would cause any strange noises.

Thanks in advance for any help...

 

[Chris-P]

When press the Econ button it doesn't use the compressor just the blowers.

 

[patchoulian]

Just bumping this if I may - I have exactly the same problem on my 2007 S3. The whining noise disappears the second the econ button is pressed. The AC/climate seems to work perfectly, but the noise is quite loud. Any ideas anyone?

 

[Daveyonthemove]

Econ button turns Aircon OFF, it simply blows outside air into the cabin.
No idea what could be causing it, but it's not likely to be the Aircon if it is being turned off.
I leave Aircon on all year round so things don't seize and I don't turn into a sweaty mess.

 

[SootySport]

Sounds like the a/c compressor Bearing or it's clutch that are at fault. When the a/c is off the compressor is disengaged and the pulley still turns on the auxiliary belt. Spray wd40 on the pulley end and if it goes quiet for a short time you've found the problem. The WD40 will wear off very quickly as it is very thin, so the compressor will have to off for repair.

 

[patchoulian]

Thanks - yes, I'd guess it's something directly related to the AC - I was just hoping it wasn't the compressor! I'll try some WD40 and see.

 

[S.]

I had the same issue with aircon noise.
I've read somewhere that it's usually pulley or not enough gass in the system. Recently g65 sensor gave up on my car and had it changed and they also re-gassed the system and it seems that the noise is gone.

 

[patchoulian]

Just back from the £75 Audi fixed price AC service (inspect, empty, refill) and the noise has gone. For now

 

[Daveyonthemove]

That's reasonable for a main dealer.
I had mine re-gassed and cleaned at F1 Autocentre's for £64 a couple of weeks ago. Well worth doing especially in this heat.