Exactly what is the electrical whizz (as if some electrical motor is constantly running) heard on the outside of the car whenever it's idling? (520i)

-paasan

Maybe just a ventilator that is cooling down your engine because you are idling? Or maybe the airco?

Johan: Doubt it.. I believe it's present even with the AC off (I'll have to check it once more though). The sound is present at all times and is slightly more dominating than that of the idle engine - but still - fairly low. I also find it hard to believe that it's something cooling the engine.. the need to chill the engine isn't overwhelming at -5'C ;-)

Are there anybody else experiencing such a sound? It seems fairly obvious that the sound is frome some sort of electrical device - but why does it have to run constantly?

-paasan

Hey Paasan

IIRC then the compressor of the A/C is always on, even if you turn of the A/C, the compressor will keep working, at least, this is what I've been told about the E46 (current 3 Series).

One additional note about the cooling fan, although it might be really cold where you are, it might still be possible that the fan goes on to cool the engine if you are idling. If you are standing still while your motor is running it will generate a lot of heat, and if you are standing still, the heated air will stay close to your engine.

Never experienced it on our 02 E39 535iMan. The only thing audible then was the engine - and of course - in hot and humid weather after 'heavy' driving - the characteristic fan.

-paasan