Francesco

I noticed that when my car is idling at the lights, I can hear the Aircon unit in the engine bay running, then shutting down every few seconds (this is a kind of humming noise which can be heard over the engine; not a switching on and off noise). As I usually drive with the radio on, and don't normally have the aircon on as I live in London where it's raining 90% of the time, I don't know if it's always been like this! Is this normal? I try to run the aircon throughout the year to keep the seals lubricated etc. but that;'s usually on the highway, where road/engine noise etc. wouldn't allow me to hear the unit.

Robin 993DX

It is normal, I hear that in my car too.

Jack

Francesco:

As Robin indicated, it's normal. Nothing to worry about.