Squeaking car

belt too tight? too loose??

Belts that squeak are due to lose belts, worn belts, and misaligned belts as suggested above by these two good people. When replacing the belt, did he examine the belt to see if it was warn? There is a belt tightener to keep the correct tension on the belt, so a lose belt should not be the problem. If there is remnants of old worn belt left on any of the pulleys, it may cause new belts to slip. You should rub the belt pulleys with a cleaner, like as asatone to resolve any residue. Then using some whiteout, place a small dab in the center of the belt and start the car. If it is true, there should not be any movement in the white mark as it spins around. A visual check also can tell if the belt is off line. Sometimes there are shims to adjust the, less say A/C pump, to put it into alignment. If there was any work done that caused a pump to be removed and the shim was not reinstalled with the shim, than there is a miss alignment. There also is a spray to use to put grip on the belt to help. Also a good belt will work better than a cheep one due to what the belt is made of. Make sure the size is what is needed. Sometimes there is an inch difference and the belt tightener is not fully making the tension correct.

Unless something is drastically out of alignment it is Rubber build up on a pulley or several pulleys. Rubber against rubber squeals like a corvette burning out. Clean the pulleys with something that will break down the rubber and evaporates not diesel fuel it's an oil. I use gasoline to cuts the rubber off the pulleys with a wire brush and after several applications is clean and free of residue. I like Gates belt, good quality, cheap belts do as you prescribed. Good luck.

belt pulley makes squeaking noise when belt pulley bearing are going..

Well ya if a bearing is going or out. All components i.e.water pump, alternator, power steering pump, air pump, air conditioning, etc. should be checked. Any problems, replace the suspected problem. The question was belt squealing after belt replacement. If belts continue to sequel, it's usually rubber buildup on pulleys. Rubber against rubber squeals.

Did you check/replace both belts? There is a small belt just for the AC at the lower bottom passenger side of the motor check and replace it as well, only costs a few bucks but it's hard to replace.