I am still trying to establish the cause of a whining noise that appears to come from behind the centre console when the Air Con is on and the 'volume' goes up and down with the engine revs.
To me it sounds like a bearing.
Noise stops immediately that the AC is switched off.
Two garages have been unable to locate the source but think it is one of the pulleys being driven by the 'fan belt' being loaded with more stress when AC is on - AC Compressor, Alternator, or water pump.
When under the bonnet it is very hard to hear it but very loud when in the cabin.
I have found in the workshop diagrams a MOTOR AIR CONDITIONING LR022168 and wonder if this could be the problem but does anyone know if it runs at a constant rate or fluctuates with the engine revs? Tattoos - Why would you choose to look like the wall of a public toilet?

Item no 10 on this drawing, not sure what it is, possibly the motor that operates the air distribution flaps, item 9 on the drawing could be moved by that motor.
If so it wouldn't run constantly.
The compressor driven by the engine has a clutch so is running all the time, with the aircon on, it engages and drives the pump. That sounds to be the favourite source of the noise.

I had the same problem some months ago on a 2010 118kW xs. We started to regas the system and put inside some fluid to find possible leakage but nothing and the noise continued. The mechanic decide to change the ac compressor (the car is under warranty by the seller, I bought it second-hand) and from that moment no bad noise during my trips....