Hey im still new to the cherokee world.
here's my problem. I just change the idler pulley. But i still have a high pitch noise coming from the front end of my engine. I'm guessing its one of my pulleys but don't know which one. I have a new belt on there. So im outta ideas on what it could be. So just wondering if anyone has come across this problem before. I have a 91 cherokee laredo 4.0L

 

Hiya 204,
Maybe the alternator. I've had bearings go bad and they do scream.
Peter

 

You can usually figure out where its coming from by using a long extension or screw driver like a stethoscope. Put whichever it is you choose to use against your ear and CAREFULLY touch it to areas around the pulleys being careful not to get too close to moving parts. I have used this method effectively many times. HTH.

 

X 2 on the alternator. mine just started to go about a month ago. check if you have any draw on the battery and if you do try turnin things off.. if the whine goes away its ur alternator. If i put too much draw on the battery now, the battery guage drops and it starts to squeal until i get the rpms up and it reaches normal operating area. I've been waiting for some warmer weather to change it out.

HTH

Jesse J.