Air conditioning problem -- Help?

[SD_GR]

Hello all,

With the A/C off, the car sounds normal. With the A/C on, there is an intermittent chirping or squealing noise.

The photograph shows the A/C compressor. In the middle of the pulley attached to the compressor is a "triangle." With the A/C off, the triangle does not spin and there is no noise. The pulley does rotate, but the triangle does not. With the A/C on, the pulley rotates and the triangle does move, but does not move at the same rate as the pulley. It seems to "lag" or to be unable to keep up.

The triangle can be spun freely by hand with the motor off. I'd expect this anyway though, since the electromagnet is not engaged, right?

Belt tension "seems" normal by hand (the maximum deflection at the midpoint of the belt is less than the width of the belt -- crude measure but that's what I've got).

So... Belt problem (my hope)? Clutch problem (second best scenario)? Compressor problem (worst ca$e $cenario)? Something even worse than that?

All help appreciated, as are any suggestions for parts sources (I checked the dealer price for a compre$$or in case I need one, and it was "ouch").

[Djart]

compressor will not kick on if the freon is low. Get a can of 132a and a hose with a gage. Hook to low side which should be marked L near the passenger fire wall. Put freon 134a in system until either the compesser kicks on or your low side pressure gets out of speck. Look around the forum for the specs. also make sure you have the car running with AC on high. Once the pressure builds the compesser will kick on. If it kicks on you most likely have a leak. Check AC hoses for oil , most likely it is a stuck Evac valve. this part is up under the dash passenger side. Look around forums there is a fix for that as well. good luck. only try to fix if you are willing to have a pro correct what you fix!! Enjoy

[SD_GR]

Bump for help...

More info:

The compressor does engage as I mentioned above, and when it eventually "gets going" I cannot make out whether the chirp is still there or not. I took a closer look at the belt, and it could use some tightening, but I do wonder whether that's the issue. The source of the sound does not seem to be the idler pulley, though I could be mistaken -- and sincerely hope I am!

Any advice appreciated. Anyone run into this? Anyone have ideas or see a silver lining somewhere?

Oh -- is it just me or will I actually have to remove the alternator in case I need to replace the compressor?

[SD_GR]

compressor will not kick on if the freon is low. Get a can of 132a and a hose with a gage. Hook to low side which should be marked L near the passenger fire wall. Put freon 134a in system until either the compesser kicks on or your low side pressure gets out of speck. Look around the forum for the specs. also make sure you have the car running with AC on high. Once the pressure builds the compesser will kick on. If it kicks on you most likely have a leak. Check AC hoses for oil , most likely it is a stuck Evac valve. this part is up under the dash passenger side. Look around forums there is a fix for that as well. good luck. only try to fix if you are willing to have a pro correct what you fix!! Enjoy

Hi! Thanks for the response! I have cold air at any time. I should have been clearer -- the A/C works fine as far as cooling goes, but I have a chirp to go with it though, and I'm wondering whether the compressor is about to seize or whether it's a simpler mechanical problem.

The compressor kicks on now, but it seems that the chirp occurs when this happens and the clutch mechanism seems to lag slower than the pulley. After a while the clutch mechanism (I'm looking at the triangle) spins quite fast, but initially it'll go in spurts and seem to want to stall, as if it's binding.

[SD_GR]

Update

Removed belt, examined, looked OK. Checked the idler pulley, it spins freely and I could not get it to generate a noise.

I replaced the belt and tightened it more than it was originally. Now the "triangle" part does not lag at all; it follows the pulley when the compressor engages.

However, I still get a noise. It's not the same noise, but it's audible in the engine bay. It's a bit of a chiiiiirp or rrrrrrrrrrrrrrattttttlllle when the compressor is working.

Cold air inside the cabin as always.

I have no idea now if it's supposed to sound this way and if it "always" did this, since the only thing that got me looking into the A/C was the chirp I got two days ago before I tightened the belt.

Does anyone's compressor make any noise or should I have someone expert have a listen at a shop locally?

Thanks again!

[06wrx4me]

Sounds like a clutch squeak or a bearing noise. As I recall you have high mileage and are in So Cal so chances are your unit as seen its share of use. Could be a bearing or clutch going out on it. Unfortunately shy of removal and disassembly I know of no other way to check, and at that point you might as well change the compressor.

My advice:

If you can deal with the squeak let it be. If you cannot, dig in.

FWIW its hard to hear little squeaks since I changed all tranny bushings to Urethane. Also hard to hear over the interior rattles.

[SD_GR]

Thanks for the advice!

When a compressor seizes, does it damage other components of the system? In other words, if I were to just let it be and see what happens, and the worse happens (the noise is abnormal, the compressor fails) do I risk further damage? If not, I may as well take my time about finding a replacement compressor (I'm not looking forward to it).

Thanks again!
SD

[06wrx4me]

When a compressor seizes, unless the clutch seizes, all that happens is loss of AC functionality. As long as the system isn't "opened" (ie lines removed and left VTA for long periods of time) the condenser, drier, etc should be unaffected.

Now if the clutch seizes (which doesn't sound like your issue) itll cause drag on the crank pulley which could contribute into side loading and potentially accelerate main bearing wear.

[SD_GR]

Thanks very much, there's nothing like being able to make an informed decision!

Cheers!
SD

[Toolz]

My car has done this since I bought it, when AC is ON, you get chrip every couple mins (3-5)
Dealer told me it was normal
I live with it, aside from the sound of a bird under the hood I see no reason to worry about it.

[SD_GR]

How long have you owned the car?

[Toolz]

How long have you owned the car?

1 Yr...I bought it from a Subaru Dealer, and took it back to them twice for this noise, first they tightened the belt..2nd time they said it was normal. I don't think they could figure it out.

[SD_GR]

Took it to the dealership and they made everything right as a warranty repair.

Do you recall what they replaced and/or did?

[SD_GR]

Thanks, sounds reasonable. If the system is opened to moisture the dryer may become saturated from what I've read. I've never replaced one though. I'm just going about life with a "let's wait and see" attitude at the moment.

[jordieb213]

find anything out about this?

an a/c compressor will engage and disengage as it builds pressure while the a/c is 'on'. The cold is created from the condensing and expanding of the freon....so you can't have the compressor kicking all the time. That is why you would hear the chirp at different periods, if your skin is realllly sensitive, you will be able to feel the temperature difference before and after the 'chirp' aka when the compressor is on and off.

but, to answer your question, i would not worry about it now as long as it is keeping you cold, it will probably chirp for a while. think about the rpm's that compressor clutch is trying to match hundreds of times a day...it's gonna chirp...and eventually it will be time for a new clutch

::run on sentences for life::