Expert: Sean Halliday - 6/28/2006

Question
Hi,

I've got an AC problem with my 1997 Saab 900se 2.0L turbo.  It's got Automatic Climate

Controll.  When I use the airconditioner I get a fast ticking and sometimes a whining sound

that changes pitch up and down.  Both are linked to engine speed - the faster the rpms the

faster the noise.  

When I use the economy feature (engages the clutch on the compressor) the noise stops

immediately.  They sound like the noises a fan might make from rubbing its shroud but I

disconnedcted the heater/ventilation fan and the noise continued, the radiator fan (there's just

one) can be off when the noise occurs.  It's hard to say where the noise is comming from I

hear it loudest in the cabin from the vents and a screwdriver up to the compressor and my ear

makes some noise, but I'm not sure if it's normal or not.

On a possibly related asside one of the high side lines rattles excessively at certain rpms.  My

own diagnossis leans towards a compressor problem (the belt is a single serpintine with a

tnesioner and is in good condition) or possible an air pocket or something in the refregerant

lines.  Maybe both?  I was looking for your opinion and some thoughts about further

diagnossis and how to go about fixing the problem.  Thanks,
Dan

Answer
could be your compressor ,very unlikely its an air pocket,if your a/c is working ok,try taking off the serpintine belt and start the car up to see if the noise stops,its ok to run the car with no belt for a min or so,,,and with the engine off turn the a/c compressor by hand see what it does but it sounds like the compressor making the noise,as for the rattle try and tie the line down to stop it from rattling as vibration causes it to leak eventually or even break.