Whirring noise from A/C coming from front..

[grahamtwatson]

2002 996 Cab C2, 24000 miles.

A minute or so after I turn on the A/C in my car, I get a whirring/whining noise which seems to be coming from in front of the dashboard - from inside it sounds like it's coming from the battery compartment. The noise is engine speed dependent, and once it starts it can be turned on or off via the A/C switch. It's obviously A/C related, but does anyone have any idea what it could be? I'm hoping it's nothing more serious than that coolant needs topping up (is there any way to check this myself) but I suppose it could be something worn or broken...

Any ideas anyone?

Cheers,

Graham

[Loren]

Look for some similar posts here and in the Boxster section (same A/C mechanism). I seem to recall some issues with foam or weatherstripping hitting the fan.

[Johnnyceesred]

I had similar symptoms (although not continuous) and the OPC and I believe it was the small intake fan for the A/C system sensor on the passenger side for sensing the interior environment. The thought was some foam or trim behind the dashboard was catching on the blades. The sound was reminiscent of small ball bearings rattling in a plastic container. I just turned up the volume on the CD/radio to compensate!!!

The problem seems to have fixed itself otherwise I think it woud have been dashboard removal.

Hope this helps.

Rgds

John

[grahamtwatson]

The noise sounds (unfortunately) more like a rumbling bearing, and doesn't vary with the fan speed. I can't track down its exact location, but it does seem to be coming from deep in the center of the dashboard....

[Johnnyceesred]

Hi Graham,

As the problem you describe: -

1. Can be started and stopped by turning on and off the A/C system

2. Doesn't vary with air circulation fan speed

3. Sounds like a bearing rumbling

would back up my suggestion that it's the intake fan to suck air in for A/C cabin environment sensing function.

When I had my symptoms the sound seemed to come from inside the dashboard somewhere between the driver's end of the passenger side airbag cover and the central binnacle for the A/C controls, radio etc.

If you put your ear to the round aperture on the passenger side of the dashboard (as shown in attached photo)can you hear the sound more clearly?

Rgds

John

Edited January 7, 2007 by Johnnyceesred

[norton-sp]

im very interested in the soliution to this as i have exactly the same problem..also when i accelerate hard it makes a "rattling" noise... but only only on hard acceleration!!

[demosan]

The noise sounds (unfortunately) more like a rumbling bearing, and doesn't vary with the fan speed. I can't track down its exact location, but it does seem to be coming from deep in the center of the dashboard....

graham,

You could remove the cabin filter which is accessed through a cover under the glove box on the passenger side. Once you remobve the cabin filter you can access the fan and it can be removed by removing three mounting screws. there must be a DIY set of instructions for this procedure move detailed than my instructions. Using this technique may avoid a complete dash removal, which I undwerstand is a rather major project.

Good luck!!

Demosan

[demosan]

The noise sounds (unfortunately) more like a rumbling bearing, and doesn't vary with the fan speed. I can't track down its exact location, but it does seem to be coming from deep in the center of the dashboard....

graham,

You could remove the cabin filter which is accessed through a cover under the glove box on the passenger side. Once you remobve the cabin filter you can access the fan and it can be removed by removing three mounting screws. there must be a DIY set of instructions for this procedure move detailed than my instructions. Using this technique may avoid a complete dash removal, which I undwerstand is a rather major project.

Good luck!!

Demosan

graham,

My original note I sent yesterday is incorrect in providing info as to how t oaccess the cabin filter. The info I sent you pertains to a MB SUV. I was in a MB owners forum and got my signals crossed.

Sorry for the confusion!!

Demosan