air con pulley - E46 318

[Fimbo]

I had my head under the bonnet today and noticed that the pulley on the far left of the engine (which I think is linked to the air con) kept stopping and starting. The belt driving it was still running over the pulley but something must have put a brake on it spinning round. It was happening every 20/30 secs. Is this normal?

[Vee]

Don't think it's normal.
Rather than the pulley being stopped, the belt might be slipping.
Is you car a manual ? If so, it's a realtively easy diy jo to replace the belt. If auto I think a tool is required to remove some sort of fan coupling - sorry for not being more specific, mine is a manual so no experiecne of autos).
The belt is about £10 from BMW iirc.

[buffly]

This is normal... The part you can see spinning is the air-con compressor, and is actuated via a small clutch every 20 is seconds. Nothing to worry about. If there was no gas in your air-con, it wouldn`t spin atall. Hope this helps...

[Fimbo]

Thanks for your responses. I had the system re-gassed a couple of weeks ago and hadn't noticed it before - when the system was being regassed there was very little in the system which seems to fit in with what you say. Glad to hear it's normal.

Neil