I have a '98 XJ w a 4.0, 145k, running good. A couple of weeks ago it started making a high-pitched squeaking noise at start up and while running that seemed to get quieter as it ran. Figured it was the serpentine belt and/or tensioner pulley. Took it to my local shop today to get the new belt and pulley put on, the engine still makes the noise. Mechanic there said it sounds like it's coming from the engine itself, may be a camshaft or valve. They don't do big engine repair and he din't want to diagnose it for sure, said I should take it to an engine shop. Before I start dumping more money into this, thought maybe someone here could ID this noise.

 

cant open your file.

squeaks can be be a belt, if it gets oily it can squeak if new belt was placed on an oily pulley, it will get oily and slip perhaps making noise.

Valve train noise is usually not a squeak, rather a tap tap, or click click noise.

A bad bearing on a water pump, fan, steering pump, a.c. compressor, alternator may make a squeak noise. remove the belt and hand spin these pulleys, wiggle to check for looseness.

An intake leak can make a whistle noise that might be called a squeak by someone also..

 

On my 98 it was the distributor that started squeaking. To find it I did what robsjeep said and checked all of the pulleys by hand, I even started it briefly without the belt on to see if the noise was still present. Then because it was still making the noise I used a mechanics stethoscope to pinpoint it at the distributor. I found a writeup on here that showed how to take apart and clean the distributor, then I lubed it up with some white lithium grease and put it back together. It has been working noise free ever since and that was over 3 years ago.

 

It could also be the harmonic balancer...looks like it's time for some good ol' noggin pokin

 

Video opened using VLC. I had to slow it down to even hear the high-pitched squeak. It sounds like a bad bearing to me. I didn't see any wobble or any rubber sticking out, but have a good look at the harmonic balancer (the big pulley on the front of the crank). Sometimes when the rubber between the inner and outer sections fails, the outer section can shift backwards and start rubbing the timing cover on the front of the engine.

 

Thanks a lot for the replies! The distributor is relatively new (35k old), but i'll check it. The noise happens even without the belt on and they checked all the pulleys.
I did more poking on here and found this video that sounds pretty much exactly like my engine. Thinking it may be time to redo the pushrods/lifters/rockers?

 

It's from this thread: https://www.cherokeeforum.com/f59/ch...-4-0-a-181432/

 

1. Stop throwing parts at it.
2. Get one of these.
3. Put it to work.

 

Like $5 at Hobo Freight. And, you know what? I don't care how "new" parts are these days. They're mostly plain old junk right outta the package. NEVER get fooled by the age of replacement parts. The originals lasted over 100,000 miles and the replacements barely go 2 years. Thanks China!!!

 

Cute kid. It's a really handy tool until you accidentally get it in the fan blade. A length of hose to the ear also helps.

 

You do know the engine isn't running in that photo, right? LOL.

 

Yeah. I was speaking from my own personal experience of not being careful around the fan.

 

The little fan on the alternator will get your attention also!!

 

So does a cat caught in the belt. Needed the hose for that one.

 

Yeah, been there, done that!