JCGonzalez92

What could be wrong with it? I just got it and the ac runs good after awhile but right away when i turn it on it makes a loud screeching noise and gets louder when I drive. Need some help, thanks in advance!

sik_xj

It happens.
Take your belt off first, inspect it.
If it looks good, then proceed to taking some light sand paper or wire wheel and take it to the water pump pulley. It probably has some pitting and rust on it. While the belt is off, do the same to idler pulley. Those are the only 2 pulleys on the serpentine system that the back of the belt rides on.
Put the belt back on and your squeaking should be gone.
If its not then you may want to look at a new belt. If you do that then the ac clutch is going out and thats a whole different boat.
I would start with the cheapest and easiest and work your way up.

The reason behind the belt doing this while only the ac cycles on is that there is much more drag and resistance and the pitting, rust, and build up where the back of the belt rides causes screeching.

JCGonzalez92

Alright thanks, Im gonna work on it in the morning. ill tell let you know how it goes

sik_xj

not a problem, turned on my ac recently and I was surprised.
I just did this a while ago and it seemed to clear up most of the noise.
It shouldnt take longer than a half hour to do.

TheCK4x4

Yeah check the belt, mine did it real bad before then I replaced the belt and it still did it....then thought why. And it wasn't on tight enough. Tightened it and now fine

sik_xj

Good call, I just assumed that the belt was tight.
However I have seen that most loose belts will squeal all the time when they are loose, rather than just when the ac is on.

Brian3676

It seems like Jeep belts have to be much tighter then other car belts or they squeak. Almost like the harmonic balancer gets worn and the belt does not grip it as much, then it turns fine with just the standard accessories on it, but turn on the AC and its too much.

A55MULL3T

I chased a squeel gremlin in my XJ for quite a while trying all sorts of tests and tricks, (spray water on it, changed an idler pulley, adjust and readjust etc etc) i even tried a new belt, and before installing it took a copper bristle brush to every pulley surface i could reach. the new belt worked for a while until it became visibly glazed again and started with the squeal. granted not as bad as it was?, but still kinda chirpy. now it kinda comes and goes, seemingly when it gets a little warm and dry underhood, its not anywhere near as bad but im over it. the old belt that i took off i gave to my buddy and he crosshatch scored it before putting it on his ZJ, no squeak whatsoever. still. so...for what its worth. good luck man. oh yea, during and since all this?, i seemed to notice almost every jeep i see chirps or squeaks a tad...I remeber even seeing one on a TV show and it was doing it..thaaaats it....im done, she doesn't overheat and I love her....