AC Compressor Making Noise

I have a 98 XJ 4.0. I just rebuilt my cooling system, new rad, hoses, thermo, antifreeze. I also replaced the serpentine while I was in there. Before I did this, and after, I sometimes get a loud squeel from the engine, like when you have a loose belt. It goes away fairly quickly, it can start up at any time, but mainly when you are turn on something, anything from the headlights to the AC. I think it is probably the AC compressor clutch. Does anyone know of a way I can check this for sure? Second question, does anyone know where I can find just the compressor clutch?

Thanks,
Sammer

Check the tension on the new belt, if it is too tight you can damage the bearings on the idler, AC compresser alternator etc.. The last time I did it it cost me an alternator.

Any parts store should be able to get you an AC clutch, but im willing to bet your belt is slipping. i thought mine was tight till i used a belt tension checking tool and it wouldnt even register on the gauge. you need to get it pretty tight, mine moves about a quarter inch when i press on it and the tension gauge says its right on.

I would first suspect belt tension, but If you are sure you have the belt at the proper tension, I would first suspect the alternator since it was doing this before you changed the belt and it squeals when you turn on the headlights. If it is the AC clutch, I don't know why turning on the lights would cause it to squeal. Did you turn the alternator by hand while you had the belt off? I had a sometime squeal that I couldn't pinpoint. While doing the cooling system, I tried to turn the alternator pulley and couldn't even move it. Local shop did the bearings and brushes for $40.

There are many sources for the clutch. However, unless you want to change just the bearing, it seems to usually make sense to go ahead and replace the compressor/clutch as a unit since the clutch alone costs almost as much as the compressor. Others may have a different opinion.

GrimmJeeper posted while I was composing (I'm slow). I had to tighten mine a lot more than I thought to get rid of the squeal with my new belt. I just did it in small increments until the voltage gauge reading was right and it didn't squeal when turning on the AC.

The people at the local NAPA look at me like I'm some kind of alien life form when I've asked on two occasions about a Krikit tension gauge. They even looked in two books and solemnly advised that they could find no reference to such a device. Guess I'll get around to ordering one some day because I am concerned about having the belt too tight.

I have a "whistling sound like a boiling tea pot" would that be the AC compressor or the viscouse connetor for cooler fan ?

Thanks for all the advice everyone. I just ordered a Gates Krikit II V-Belt Tension Gauge off Amazon. So I will have a reliable tool to check the tension with. I'll post after I check that out.

Sammer

Oseberg said:

I have a "whistling sound like a boiling tea pot" would that be the AC compressor or the viscouse connetor for cooler fan ?

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Check your idler pulley, sounds like the bearings are shot. You can get the new pulley/bearings at any auto parts store for around $20 or so.

Last weekend I replaced the idler pulley and re-tensioned the belt. Noise is gone (knock on wood). Thanks everyone for your help and suggestions.

Sammer

if that same problem comes back hopefully it doesn't but mine did 4months ago and i have replaced everything possible and i think now i have an idea what it is .But i had to go through a water pump from cranking the belt tensioner,harmonic balancer,3 goodyear gator backs,idler pulley.I thought my prob was the ac clutches so i took out the ac clutch fuse under the hood so the ac wouldn't kick on w/ the heater on. it still seemed that everytime i turned the heater on 2 or 4 speed while the elec fan came on and the headlights on it still squealed bad, my voltage droped real low and my headlights dimmed.Then when it rained and i had all those on plus the wipers, my check gauges light came on and the voltage gauge was bottomed out.when i got out and inspected the squealing i happened to glance down at the belt as it rode true over the pullies i noticed that when it came around from the ac to the water pump it was kinda wobbling.So tonite it was real cold and just finally ticked me of bad so i got on here and have came to the conclusion that it is the alt.from nobody having had all the exact problems i have they all could possibly lean toward the alternator.So i'll take the belt off tommorrow and see if i can turn it by hand to see if i get alot of resistance from it.Hell if i dont i think i still just might replace it anyways for the new stereo and winch i getting ready to order.Enough babbering i'm done if you run in to this problem keep this thread in mind

sbilbrey said:

I have a 98 XJ 4.0. I just rebuilt my cooling system, new rad, hoses, thermo, antifreeze. I also replaced the serpentine while I was in there. Before I did this, and after, I sometimes get a loud squeel from the engine, like when you have a loose belt. It goes away fairly quickly, it can start up at any time, but mainly when you are turn on something, anything from the headlights to the AC. I think it is probably the AC compressor clutch. Does anyone know of a way I can check this for sure? Second question, does anyone know where I can find just the compressor clutch?

Thanks,
Sammer

Click to expand...

I'm in the same boat! lol.:hang: I tested the battery, Alt. and it reads good. But when the AC clutch kicks on it squeel like a pig. Not all the time though. I changed my belt due to 2 big cracks in it. It dont squell any more but it still has a voltage problem. My lights still go dim and my amp gage gose south. If you have figured this out . Please let us know what you did.

Thanks in advance.