1994 sierra "squeaking noise" under the hood

[LOUD-ASS-SIERRA]

I have a 94 sierra 5.7L v8. Recently ive noticed a slight squeaking noise under the hood. Its been getting worse and worse. Starts up just fine, runs great, etc, but there's something obviously loose or out. I guess im just asking if someone knows what it might be or has had the same problem. You see i'll start it and it wont start squeaking until about 5 minutes later. Now it is only a "squeak or a squeal" noise not a crackling or clicking which makes me to believe it is very small problem. It's real annoying though hearing it driving down the interstate or at a red light. It's not a constant squeak either just spuratic and random, not in a pattern at all, just squeaks like a mouse. I've tried spraying some things down but that did nothing. My only guess is the belt (which looks fine) or maybe a barrings out in the alternator. HELP ME SOLVE THIS DAMN PROBLEM!

[Marsal420]

I own a 1994 gmc sierra myself and i found that same exact problem. On mine it was the Ac Clutch because the bearings were just gone and it was rubbing up against itself. Which then made that bad squeek. Other then that i dont know i sprayed some engine cleaner on it or you can also use ( Wd-40) and that should work atleast up untill you can get a new one they run around 200 for a new one and i dont feel like spending that much so i just keep spraying heh. Hopfully this helps you out man. Peace

[strmn94]

that is what it sounds like. i have had 2 compressors go out. and using the WD-40 wil only work for a short time.
one of 2 things can be done.
1) remove the belt, and say the heck with A/C
2)replace the A/C Compressor. be sure to take it and have the system cleaned out of the freon before removing the compressor and replacing it.
once you get it replaced then go to where they removed the old freon, and have them vacuum it and charge it up.

[LOUD-ASS-SIERRA]

Yeah im assuming it is something with the a/c. Ive sprayed some parts down and changed some fluids and it seems to be fine now, havent heard it yet but we'll see in the future. Thanks for your help and knowledge.