Hey guys. I have a 1990 xj that is actually running quite well. The only thing is, is this chirping noise coming from one of the pulleys. We thought it was the power steering pump so we replaced that but it's still there. Sometimes it goes away and sometimes it doesn't. The worst is when I'm idling. Help would be greatly appreciated.

 

prolly the idler pulley under that is built into the mount under the air conditioner mounts.

best thing to do is pull the serpentine belt and start spinning the pulleys by hand to feel for the bad bearing.

 

How old is your AC comp?

Just had mine melt down on me lol

Started as a chirp, ended in smoke.

 

Thanks cage ill do that soon.

As far as I know it hasnt been replaced ever. Lol

 

remove the belt and start up the jeep to see if the noise goes away. if it does then it is the belt. if it is still there like mentioned above spin each pulley till you find the noise. i cheat and use an air die grinder with a scotch pad and spin it with that. not the best idea but it gets those pulleys spinning fast!lol

 

Umm, if he takes the belt off the pulleys won't be spinning so the squeak will go away no matter what.


Get a belt tension gauge and tighten the belt to the proper tension. (Search on here and you will find it) the 4.0's need a surprising tight belt.

If that does not fix the problem then remove the belt and inspect the pulleys one by one. If you can't locate the source of the noise you can reassemble and lubricate the pulleys one by one (running the engine in between) until the chirp goes away.

Best of luck.

 

Water pump.

 

That is how I found the noise coming from my tensioner pulley. I just shot some WD-40 on the pulley bearings until I found the one making the noise. just try to keep the oil off the belt.

 

Thanks guys.
I'll find it sooner or later with all of this to do.

 

I would recommend trying a stethoscope. I found my bad idler pulley that way. Place the stethoscope rod on the shaft or the bolt on each pulley (not the moving parts or you may get hurt) you will hear a grinding noise coming from the bad one. If the pulleys are good it most likely is the water pump, or ac compressor.

 

Or fan clutch

 

[QUOTE=offroadman1973;1400538] remove the belt and start up the jeep to see if the noise goes away. if it does then it is the belt.

 

Sorry to resurrect an old thread, but my a/c has started making grinding noises too. Sounds like a bearing, but INSIDE the unit. I'm assuming it would be cheaper to buy a new or reconditioned unit rather than trying to tear the old one down and replace a bearing???
As it is, the a/c is still working fine, and I'm pretty certain the pulley bearing is OK. I put a mechanics stethoscope on it, and the noise appeared to be coming from inside the unit.

 

Or the distributor, another project I need to do ASAP

 

I second that, try distributor, dry / worn plain bearings chirp, just pulled my distributor due to chirping when idling and cold, oiled the top bearing and silence, must figure out a way of getting a better oil supply in there, anyone any ideas.
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