zombiehunter99

Replaced my alternator yeasterday. (Was on its way out ). And nowxi got this chirping noise. It aint constant chirping it chirps twice (chirp, chirp) then stops for about 2 -5 seconds then chirps twice. It does this mainly while driving I tried to make it make the noise in park and rev my engine so I can pinpoint where its coming from but it dont. It only does it while driving. I tighten my belt pretty tight can turn it side ways about 1/2 inch cause I heard xjs need belt tight than normal cars. It mainly comes from front under hood. Maybe I tighten my belt too tight . What u guys think. It never done this til after I put my new alternator in....

landude

Does it do it only when defrost or AC is on?
I'm thinking belt is still a little loose and it's the compressor chirping.

DFlintstone

Tight, tighter, tightest the darn new belt would still chirp.

Finally in desperation I went out there with a bottle of Dawn dish soap and the garden hose. Idling, I got it wet, then squirt soap on both sides, rinsed some, and soaped a little more. Let it idle a minute all soapy. To end, I ran the hose slow on it running for a couple minutes. Bingo! That solved it. There was some sort of coating on the new belt? Idk.

I normally run my belt as loose as I can, and still have the alternator not slip with the blower on high, and lights on brights. Puts less strain on all the other bearings. Radi pointed out a cool tip. After it might have been slipping, (voltage has been low), see if the Alt. pulley is hot. I want to go back and loosen it a tad now.

zombiehunter99

Sorry for late reply just got off work. Im going to tighten belt a little more I can push it down about an inch now will reply in a bit on update

Roler

It can be helpful to actually open the hood and listen where the tjirp comes from...this will give you and idea about a pulley and/or belt.It'll be one of those two causing the tjirp.
I think the recommended tightness of the belt (sure there is an official number for this) is about max 1/2 inch 'depression' possible at the middle of the longest belt 'stretch', iirc.

zombiehunter99

it doesn't make the squeal noise at idle or anything like that it does it when you're driving down the road under a load but have someone look at my jeep and my idler pulley / tensioner pulley is kind of bent a little bit he said I may be causing the problem. Doesn't do it at idle only while I'm driving. I bought a new idler pulley installing it now. I did notice with belt off my mechanical fan pulley has a little movment not much is this normal. .

Roler

Pulley's should be tight...Anything with a play/wobble will only worsen over time especially with a tight belt around it..

zombiehunter99

Well done puting my jeep back together. And started it at idle no noise. But like I mentioned earlier it only did it while driving so im going to drive it tomorrow too tired now cause of work olus im going to the jw to pick up a few misc items.oh the fan clutch has movement not the pulley cause with belt on the clutch fan moves a little.I now have new wp replaced about 6 months ago along with harmonic balancer idler pulley and alternator. The previous owner replaced the a/c clutch n pulley before I bought it. New belt dayco. I hope the squeak is gone will find out tomorrow. ...

zombiehunter99

Well that darn squeak is still there fairly new belt new idler pulley. I dont know what this darn squeak is coming from it only does it while driving 25mph and above doesnt do it at idle or in oark. Doesnt matter if defroster is on or off. Idk

scottmphoto

The belt's on our XJ have to be insanely tight so they don't squeak. Also, you might check your harmonic balancer. They are a two-piece design with a rubber isolator in the middle. Over time, it can wear out and start coming apart. Mine did this. It was just out ever so slightly but it was enough that I had to replace my HB. I went through a couple of belts and was going nuts trying to figure out why it was STILL squeaking. I replaced the HB and the squeak has been gone now for over a month. I don't have a photo but if you search here for harmonic balancer, you'll find some photos of what I'm talking about.

zombiehunter99

I replaced my harmonic balancer when I replaced my water pump . So idk it never did this until I replaced my alternator. ..

DFlintstone

zombiehunter99

For some reason the squeak stopped. Maybe some grease got on the belt

Windsor 90 Laredo

One quick old timer trick is to hold a stick of chalk against the belt while engine is running to eliminate the chirp. I've never done, just a thought if it comes back. I recently started getting a chirp, but only when first firing up in the morning.