SaabCentral Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
102 Posts
Discussion Starter · #1 ·
Hi Saabers,
Well the weather is heating up here in Oz (and quickly!) and I've noticed over the last few month that when my A/C is on there is a whirring or almost a grinding sound coming from it at low speeds - right hand side behind/ in the dash.
At cruising speed there is no noise at all, but when slowing down (and down shifting) or idling at lights the whirring noise kicks in and seems to increase/ decrease with the revs of the car.
It is a 900 s spec so it is the manual A/C not ACC and it still blows nice & cold. Just wondering if this is perhaps a belt issue or something more serious like the compressor on it's way out? It hasn't got worse or better over the few months I have noticed it but I don't use the A/C a lot.
As far as I know there has been no previous A/C issues with the car (which also means probably no recent maintainence either)
Just wanted to get your thoughts prior to me going in for a service.

Thanks in advance
Shaun
 

·
Registered
Joined
·
595 Posts
Take a look at the ac pump pulley as the compresser turns on amd off. You will more than likely see the pulley shimmey-wobble a little bit. There is a bearing under there that probably launched. I had the same problem this summer. I ended up swapping the whole pump with a used one from E-bay.
 

·
Registered
Joined
·
4,293 Posts
Checking the condition of the belt and the ilder pulleys is a good idea in any case, sound can fool you, and adding the compressor load to the serpentine belt can make another problem audible.

It is usually possible to localize a sound that comes from the belt area using a mechanics stethoscope, one with a long metal rod that you touch to a pump casing or a compressor casing, one at a time, until you find the one making the noise.

It could be the compressor pulley, which has a magnetic clutch that engages to run the compressor, the compressor itself, or the AC system could just be low on oil and/or refrigerant. It is possible to loose the oil a little bit at a time through a small leak, depending on where the leak happens to be.

The first step is to determine if the sound is present all the time, or only when the AC "cycles on".

The belt spins the pulley any time the engine is running. The clutch engages with an audible click, when the AC cycles to start running the compressor. (audible listening over with the hood up). That helps to localize the noise.

Good luck!
 

·
Registered
Joined
·
21,583 Posts
I believe that a tear down of the compressor clutch will prove Eric to be correct.

At one time, I think, the front end of the compressor could be removed and replaced without breaking into the Freon... ..These newer cars I do not know about...tiny engine compartments,poor accessibility..
 

·
Registered
Joined
·
4 Posts
Yeah, mine does that all the time Shaun, I've been told to wait till it dies then replace...if I get sick of it I might take these guys' advice and swap it over.
Bill (98V6 900S)
 

·
Registered
Joined
·
102 Posts
Discussion Starter · #7 ·
Hey hey,

Thanks so much for the reply - I am gonna check it up on the weekend with my uncle (who has an assortment of old Euro cars) so of course he has a bunch of tools to help me diagnose/ fix/ make worse etc etc hehehe
 

·
Registered
Joined
·
21,583 Posts
As PMI has so astutely stated, examine the pulleys ; these are a service item good for 30 to 60k miles.

The compressor clutch can be removed; special pulling tools are necessary..
 
1 - 8 of 8 Posts
Top