High Pitched screaching noise in front of engine

For the past 2 months. Every time I start my 1996 Grand cherokee the front of the engine squeels a very high pitch noise. Sounds just like a seriously loose belt. I have changed the serpentine belt, then the belt tensioner and it still does it. Once in a while after I drive for about a hour the noise will stop. But the noise is always there when started up and at least for an hour or so. What is it?

is constant? when you rev up the engine does it go away?

is constant? when you rev up the engine does it go away?
I used to go away when you reved up the engine but that don't work anymore

It could be any of the belt driven accessories. You might have bearings going out. If the PS pump/AC compressor/alternator is binding it will cause the belt to slip. Freind of mine had the PS pump lock up on him and he had to keep a foot on the gas to keep it running. Try listening for where the noise is coming from with the hood open and you standing in front. Be careful though. You don't want to get any loose clothing or anything caught up in there. You said that you put a new belt on. Is it showing any signs of wear?
ByronP

had a sreeching problem, thought it was the belt, but my water pump was on its way out.

It could be any of the belt driven accessories. You might have bearings going out. If the PS pump/AC compressor/alternator is binding it will cause the belt to slip. Freind of mine had the PS pump lock up on him and he had to keep a foot on the gas to keep it running. Try listening for where the noise is coming from with the hood open and you standing in front. Be careful though. You don't want to get any loose clothing or anything caught up in there. You said that you put a new belt on. Is it showing any signs of wear?
ByronP


Byron, the belt seems to be wearing fine. I did put a rebuilt waterpump on in the year 2001. steering works fine and the system is charging fine.
Still squeals alot. Today I had about 30 minutes of driving without any squealing then it came back again.

Byron, the belt seems to be wearing fine. I did put a rebuilt waterpump on in the year 2001. steering works fine and the system is charging fine.
Still squeals alot. Today I had about 30 minutes of driving without any squealing then it came back again.

warning, don't make the same chauvinistic mistake i made. "more is better" i hosed my squeeking belt with belt dressing. the squealing become so loud i was embarassed to start the vehicle. I had to replace the belt. here is something to try, but you should put your old belt on first (you will ruin it with this check hence the first comment i made)

while it is idling spray wd40/pbmax/ etc on each rotating pully (NOT THE AC) if the noise quietens?? momentarily, you have found the culprit.