aircon pulley noise
 

Got an issue with a loud noise like a faulty pulley or similar when switching the aircon on.
Noise stops when i switch off the aircon.
It almost sounds like its around near the belt tensioner area.
Aircon is still functioning and the clutch on the aircon is still activating asper the switch (on and off)
Cant remember if there are other pulleys on the aircon belt.

Aircon
 

Had similar problem with mine increasing the speed noise got louder decreasing noise got less. Fitted new pump also new condenser both looked very tired.Result very quiet now hope this is some help to you.

Peter,

Always bear in mind that engaging the air conditioning compressor places a heavy load upon the engine so an increase in noise could be a lot of things, not solely the compressor.

How many miles has your car covered since the ancillary belt tensioner was last replaced?

Simon

its done about 40,000km since belts done.
When the aircon is off i can just here a pulley squeak even now and then but pretty quiet, as soon as i hit the aircon ,the pulley squeaking sound is quite loud and sounds like metal rubbing.
Sprayed with hose and definately not idler pulley, somewhere up under engine bracket.
Power steering pump seems fine as well.
how hard is it to remove the tensioner pulley?

But was the ancillary belt tensioner replaced then? That was my question. :shrug:

Simon

I had this on my diesel and it turned out to be crankshaft pulley on its way out only showing up when load applied. So as others have said maybe look elsewhere.

OP as the car below ;) so it will be different to the diesel engine.

Car
Rover 75 Saloon MGZT
Engine
2.5
Model
Rover 75 , MGZT
Model Year
2003

All the belts were done 40k ago.
Think the issue may be the aux belt tensioner.
There is another poster on the forum who posted a youtube clip with the exact same sound but he seems to have not finished posting a result except to say he got to using soap or similar to quieten the belt.
Is the aux belt tensioner pulley plastic or metal?
Just cant quite figure out why it suddenly gets so loud only when the aircon is engaged.