couple of days ago was out for a ride and had the ac on to give it some exercise.  after a while i noticed a sound that wasnt good.  i shut it down and no more noise. today i found out the bottom pivot bolt had backed out and the compressor was a bit loose so i thought it was belt squeal. i re seated the bolt today , tightened up everything and gave it a whirl. still comes out with a god awful squeal as soon as you turn it on like its about to seize up. do you think the damage has been done?

How would the compressor belt being loose ruin the compressor?

the bottom pivot bolt was backed out and the compressor had some wobble play to it...  so that plus the belt loosening as a result may have put some awkward stress on the shaft and bearings for a while at highway speed...  this is why i mentioned

Does the squeal noise go away at any time, or is it constant? IF the compressor is actually trying to lock up, it could be "skipping" the belt on the pulley, and cause the noise. I would turn it on and watch the clutch on the compressor while running, to see if it is doing a "freeze frame" type thing...spin/stop/spin/stop(quick spin/stops). If you see the clutch doing that, then the compressor is likely done for, assuming the belt is tight, and the correct size and shape for the pulley. Assuming also that it was working ok before this started, I would prolly eliminate the belt/pulley as the actual issue if it is tensioned properly.

Another thing that could cause a problem is the clutch is just flat worn out, and not gripping the pulley as it should. If you can see a large gap(more than 1/8") between the clutch face and the pully, you might remove the clutch and check the condition of it and the pulley. Either/both can be replaced without removing the compressor, or losing any freon.

Joel Adams
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lets put it this way , it sounded so ghastly , that i wouldnt want to keep it on to see what happens...  it was instant once the switch was put on.  i know belt squeal and i was hoping thats all it was. the sound was more metallic in nature. thing is before this incident , the system was ok. i guess it could be worse... i saw a compressor and dryer on ebay for $278 , but its still money. i didnt notice any sign of oil leakage. was hoping maybe it could be refilled. just a bummer i guess.  still dont know how that long bolt could have backed out, but at least it was hangin on the rear of the bracket and i still had the bolt and spacer!

Sounds like it is either the clutch is slipping, or the compressor is failing. Compressors usually make a growling noise, but they can just break too. Take a look at the clutch....if it looks like the one in this pic, it needs replacing(pulley also). You should be able to turn the clutch by hand fairly easily, tho there should be some resistance, since you are trying to compress the gas in the system. If it has rough spots, or locks up(by hand), the compressor is bad.

A noise any time the engine is running with the A/C off is a bad bearing in the pulley, as far as the A/C system is concerned.

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"