Air Con Query

[Myles]

When engaging my air con, I can hear the clutch kick in then a small vibrating noise. Not always noticeable. It goes when the car is in gear and moving. My questions are:
1) How often does the air con compressor oil need changing?
2) Does the cog that powers the air con compressor spin when the engine is revved, ie. I leave it on tickover and the cog spins with the rest of the engine, via the V belt, but when I rev it, the cog stops spinning until tickover is regained?
3) How come so many things go wrong all at one time???!

Many thanks in advance
Myles

 

[Myles]

Anybody?

 

[Kermit]

1) The oil for the compressor is blended with the refrigerant. With time, and particularly if the air-con isn't used, the oil/refrigerant cocktail leaks out of the system - it's inevitable. So usually what happens is when your aircon feels like it's not getting as cold as it did x-months ago, the first thing is to check the level of said-refrigerant and flush/recharge the whole system thus changing the oil in the compressor. In summary, if your aircon is still cold, chances are the oil is ok too.

2) The compressor is driven continuously by the engine, just ~1.3 times faster in the Leon (and possibly others). If it were to stop when you revved it, the aircon wouldn't work when you were driving would it?!

3) Life's a bitch sometimes - and I sympathise because I had aircon trouble in a previous car... it only ever goes wrong when you need it most.