AC compressor belt keeps running off pulleys

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Hey everyone,

I drive a 1994 Geo Prizm with 130,000 glorious miles on it. I love this car and want to drive it until it goes or I go.

I've been having some issues this past year with the AC Compressor belt. My car doesn't have a serpentine, rather separate belts for the alternator/water pump, power steering, and A/C compressor.

For some reason, the A/C compressor belt keeps running itself off the pulley. Sometimes, it will stay on there fine for months at a time, however the one I just replaced only lasted 2 days before it ran itself off again.

I brought it to a mechanic when it first happened and he said the pulleys seem to be in-line, so I'm wondering what it could be. Is it that my compressor is seizing up? Could anything else be causing it?

Also, if it is the compressor, how much would it cost to repair?

Thanks for your help!

posted by  thisisbrianly

Sounds pretty weird to me. Are the pully's ballanced like not tilted one way or another? are either of the pullys bent? is their any large debris on the pully? Is the belt tight enough? are there any (if any) teeth or grooves missing from the pully?

posted by  azkid110

You car most assuredly has serpentine belts... It may have three instead of only one but they are serpentine belts none the less. For a serpentine belt to spontaneously come off, there has to be a major and simple to identify cause. There are only a few common things that will cause a belt to "run off the pulley", those being;

a. Belt being adjusted excessively tight
b. Pulleys not aligned
c. Damage to pulleys
d. Incorrect belt installation (offset)

There are other possible causes, but they are very unlikely and certainly not consistent;

a. Road debris
b. Belt icing

If the A/C compressor was locking up, you'd know it long before it threw the belt. The A/C would stop working, you'd have a hellacious noise, you'd small the belt burning on the pulley and about 75% of the time it will lock up the engine. The condition of the belt after coming off will offer a great deal of information as to why it happened. It's time for you to do some detective work.

posted by  vwhobo

Actually vwhomo, I have heard of them coming off when the belt is too loose, so that could be a fifth cause.

Is the belt in usable condition after it comes off, or is it burned up?
(according to vwhomo it would SMALL really bad)

posted by  carls47807

I bet you've heard of anal too, why don't you give that a try - homo. Quick - name 5 causes that make you a dumbass.

I sure can.

I'm pretty sure between the mechanic that checked it over, and the owner of the car, that they'd have not overlooked the belt being too loose. It would have to be loose enough to make noise - which would be easily pinpointed. That either makes you an idiot, or the car owner. I think it's you. Well, on the other hand, I know it's you.

posted by  67Coronet383

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