load strange noise.

teednab-el

Hi there,

When I switch air conditioning on in my audi A4 tdi , there is an unusual noise coming from the engine. Sounds like a worn bearing or something rubbing off some object in motion. It goes away when I switch the air conditioning unit OFF or when I hit the ECO switch on the unit. Anyway it doesnt sound good.
Anyone know whats up?

Cheers in advance

Harcrid

It's probably the bearing on the air conditioner compresssor. If you can locate this under the bonnet give it a wiggle and see if there is play in it.

spiggotpaddy

somtimes the nut on the compressor pump comes loose or it could the compressor bearing or a noisey tensioner bearing.
if things are a bit tight after crimbo you can bypass the compressor with a belt off a non aircon model but then you have no air con to keep you cool on these balmy evenings.

Owen

Mostly likely the airconditioning compressor clutch. It's electrically operated like a solenoid, when you hit the eco button it disengages the clutch so you don't hear the rattle, but when you have the aircon on, the clutch is engaged, the belt begins to spin it, and the bearing inside which is worn is causing the noise.

It'll eventually fail, and while there's rebuild kits out there for the clutch, it's nearly as cheap to get an aftermarket airconditioning compressor and fit it.