320i noise at idle

[look@u]

HI all
my (03) 320i touring has started to make a wining noise at idle,
if I give it any revs at all it stops. Any advice would be great (cheap easy fix I hope).

[SpeedIsProgress]

Is it the air con? My 325 air con makes an iritating wining noise at times, and its most noticable at idle.

[look@u]

The noise seems to be coming from around the engine bay.

[Barreti]

could be the alternator - they whine when the bearings are going.
It could also be the water pump. Mine went recently and the RAC guy told me they seem to be prone to water pump failure. Try watching the pump as the engine is running. When mine was on the way out you could see the pulley wobbling about.
A whine is a bugger to trace specificlly though.

[look@u]

Thanks for that.
Any idea on the cost of these to get fixed as I don't know what to look at or for.

[Barreti]

Water pump replacement was £268 at a BMW dealer. Thankfully for me it was warranty work