Hey guys, I got a grinding sound coming from somewhere on my serpentine belt. The belt seems to be tight and in good shape. It's a metal on metal type of sound.. like a bearing or something. It sounds like its coming from the crankshaft or water pump but i don't know for sure. Which pulleys have bearings? and do they ever go out? Any help and ideas are much appreciated thanks!

 

sounds like the bearings in either your alternator or water pump are done for... i would get a stethascope or if you dont have one use a real real long screwdriver and put it up to the pump or alternator then put the handle end up to your ear and plug your other ear....
whichever one is makin more of that noise your hearing is what needs to be changed

 

oh and btw your gunna want it to be running while you do this just be real careful haha

I am not responsible for any injuries sustainded while diagnosing your jeep

 

Ok thanks for the replies. I just listened to it again and it sounds like it could be coming from the valve cover area...? any ideas about this? Maybe it's not the belt...

 

that sounds bad! lol im not really familiar with the 4.0 i just got mine and luckily it runs like a top (knock on wood) but if there is grinding up there my guess is it nots getting oil and if its not getting oil i would say its an oil pump which would be inside your timing cover down by the harmonic balancer... if i remember right this is where you originally said the sound was coming from right?

 

Bump

 

Something that can be making a grinding sound in this area is the AC compressor. The clutch bearings could be going out.

 

You can use a length of heater hose like a stethoscope to pinpoint the source of the "grinding".

 

yeah that sounds a little safer than my redneck method lol

 

yeah sounds like its your idler pulley... it mounts right below your valve cover... loosen your belt and wiggle it if it moves it's shot.... easy fix to just one bolt and like 7-15$...

 

typical idler pulley, check it first by loosening the belt and spining it with your hand, or just replace it for good measure.

 

Ok hopefully its just an easy fix like the idler pulley. The oil pump would really suck! It's just about to turn 216,00 and its been a great jeep. Thanks for all the help guys!

 

I had a very similar problem, I just took off the belt and turned each pulley by hand to see how easily they turned. My water pump was almost locked up.

 

How would i take the tension out of the belt? i found a long bolt with two adjustment nuts that runs underneath the power steering pulley.. is that the only bolt i need to mess with? I know there's lots of write ups for this but i can't seem to find one for the older cherokees. TIA for any help. Pics would be great!

 

yeah its under the powerstearing there is two you can get to from the front and one that is easier to get to from underneath just loosen the three and it will release tention