Hi any ideas what this could be on my 2007 GS, when the aircon is running there is a hirring noise inside the car, it drops down when the eco button is selected and completely goes when air con is switched off. Any ideas would be helpful.

Regassing will probably help; am I right in thinking the air con isn't ice cold any more.

Air con works perfect no issues with temp. Thankyou

I have the same problem...

http://www.freel2.com/forum/topic20573.html

Three garages have now looked at it and think it is one of the belt driven pulleys but can't confirm it is the AC Compressor! Tattoos - Why would you choose to look like the wall of a public toilet?

Hello Charlie66, This may not be the noise you are hearing, but in the curved part of the dashboard under the key fob slot is a small round grille. This covers -I believe- a sensor that measures the car's internal temperature as part of the climate control system; it works intermittently and does make a 'whirring' noise when operating. It's not loud but can be noticeable.
There have been posts some years ago covering this.
Hope this helps.

Charlie66

Does the whirring noise increase/decrease with the engine revs? Tattoos - Why would you choose to look like the wall of a public toilet?