Engine Squeek Making Me Crazy

got a squeek thats driving me crazy...
97 xj 4.0L
its coming from the a/c compressor / alternator area
are either one of those know to squeek?
maybe there is a pully somewhere down there?

i can quite make out which component its coming from.
it seems to squeek (kinda like a chirping) in neutral and drive and it seems to speed up with acceleration. if i gun it the sound with speed up then disappear until stop accelerating.

any suggestions?

should i probably check the belt first? need to find out when it was installed.
for some reason i remember reading something about a/c compressor clutch bears?

Definitely check your belt and its tension, as that sounds very much like the issue (as suggested by dumbagain). If the belt looks at all old/aged/fatigued (including very small cracks in the rubber) go ahead and replace it with an OE belt. Some dealerships want $100+ for the belt alone, but I managed to find a dealership selling it for $46. Shop around for the best deal (definitely shoot for OE Mopar though). I have a Duralast in my emergency kit as a limp-home option, but should probably replace it with a Mopar now that I know where to get them cheaper.

Squeeks and chirping noises are usually related to the belt and/or accessory pulleys. If I were you, I'd take off the serpentine belt and do the following tests:

1) Make sure the engine is cold, then run the engine breifly without the belt. If the noise is absent then you've narrowed it down to the belt and accessories.

2) Spin all of the pulleys by hand, and make sure all of them spin freely and quietly. Spin them fast, and spin them slow while putting some force downwards on the pulley (to simulate the belt tension). What you're looking for is any grittiness or looseness, really anything unusual.

If the pulleys check out fine, another possibility is that the belt was not tight enough and was slipping on the pulleys. First I would look for any oil or other fluids that are on the pulleys, if you find anything make a note of it and then clean it off. Re-install the belt and tighten it to specs. I forget exactly what the spec is, but you should be able to dig it up in search or in a FSM. You'll need a belt tension guage to do this accurately (I think NAPA sells them).

The shadetree way to measure belt tension is to find the longest run of belt between two pulleys (on my '92 this is between the idler pulley and the P/S pump, yours may be a little different), and tighten until you can just barely twist the belt in the center of that run by 90 degrees. It should be pretty darn tight.

I'd try all of that and see what you find.

Hope that helps-

Robert

Thanks.
I will check things out and repost.
Belt seems tight and in good shape.
Might have warranty on belt. Would it b ok to use another gatorback or go with oem?

This is where having a set of stethoscopes comes in handy.

Two types: A "mechanic's" stethoscope has a long metal probe for detecting odd
mechanical ticks (lifters) and grinding noises (alt bearings). A medical stethoscope
works better for listening in and pinpointing vacuum leaks, hisses and odd whistles.

Check the distributor cap and rotor center contact. You'll need to remove the distributor
cap for this. A tiny bit of carbon build-up here will make the squeeking and chirping that
you describe.

Not sure if this helps diagnosing but this morning its 20 degrees colder out and there is no squeek.
Either metal or rubber a little "looser" yesterday.

had a squeak and eventually found i also had a small water leak dripping on to the belt

also experience worn idler pulleys causing the belt to run off slightly and squeak

seems like the noise is coming from the driver side of the engine (eventhough i swear it was around the alternator before). used some garden hose and i think its coming from pulley under the power steering unit.

seems tight to get at the idler pulley bolt. should i remove the electric fan in front? is the fan easy on, easy off?

also can i skip the a/c compressor pulley if i dont want to use a/c?

If you don't have a stethoscope bandy I use my longest flathead screwdriver with a plastic handle and press It to my ear and hold of firmly to metal components to be checked. I used this method to find out my idler pulley was bad.
I put the crewdri er on the idler pulley bolt head and whammo grinding noise. A new belt and idler and no more squeak.

Dragonslayer said:

This is where having a set of stethoscopes comes in handy.

Two types: A "mechanic's" stethoscope has a long metal probe for detecting odd
mechanical ticks (lifters) and grinding noises (alt bearings). A medical stethoscope
works better for listening in and pinpointing vacuum leaks, hisses and odd whistles.

Check the distributor cap and rotor center contact. You'll need to remove the distributor
cap for this. A tiny bit of carbon build-up here will make the squeeking and chirping that
you describe.

Click to expand...

When I want to locate a noise OR smell I use a piece of vinyl tubing, 3'-4' long, about 1/2" ID. Stick one end in your ear/nose and move the other end around until you locate the general area of the noise or the source of the smell.

Often you will also need a mechanic's stethoscope as Dragonslayer has already described to accomplish the final locating of noises.

You can substitute most any rubber hose for noises, but they tend to mask smells.

I had the same thing happen to me about a week ago. Turned out to be the idler pully bearing going bad. Its right beside the AC compressor so that possibly might be your problem. Id use some sort of stethoscope first before just throwing parts at it.