Sounds like a supercharger...

It happened last winter when I got it and just driving down the street and it starts howling and whining like a supercharger. My dad told me he thought it was the power steering. So I figure I'll wait untill it goes then the noise slowly went awaywithout any power steering issues. Last summer I didn't use the a/c because it doesn't work(i just assume it needs a charge, the previous owner replaced the system not long befor i got it). Then recintly the noise comes back. I open the hood and decifer that it comes from the idler pull or the a/c compressor. But why the winter... I'm thinking of just pulling the whole a/c system, but a/c would be nice in the summer. All the other poast mention the belt tension, its not that. Anyone else encounter this problem.

Sounds like your A/C compressor. It will cycle on and off when you use your defrost, thats why it shows up in the winter and not the summer.

Give the idler pulley a shot of wd40. It will temporarily quiet it and will allow you to determine if it is the culprit.

I'll try wd-40 but if its the a/c compressor is it because its dry (it needs a recharge) or will it need to be replased?

StuckXJ said:

I'll try wd-40 but if its the a/c compressor is it because its dry (it needs a recharge) or will it need to be replased?

Click to expand...

I cant say without actually hearing it. My A/C compressor has made a CLICKCLICKWHIIIIIRRRRR sound for over 100000 miles now and still works fine. Its more likely the clutch and not the actual pump anyway.
Pop the hood and wait for it cycle on and off to see if thats the noisy culprit. If it is then recharge it and see if the noise goes away or at least quiets.
Does the "supercharger" sound change frequency with engine RPMs? If it does, its a pully thing and not the compressor.

ah-that magic word-"winter".

idler pullys love winter when they go dry- it sounds horrific, and it`ll sound just like its comeing from the ac pump area- for right now, the pully is fine-its just dry as a bone inside...and wouldnt you know it, its a sealed bearing. It`ll scream untill it warms up and has clearence, or it`ll lock up. Ive never seen one lock yet......I had a source for the bearing itself, but lost it- it was a common NGK sealed, almost the size of a rollerskate bearing.

The day this happened to me- in winter/cold- my neighbor came rushing over thinking I had a several cats trapped under my hood stuck in the belts. Its that bad. It`ll make your hair stand up on end (maybe thats why I now have no hair).
Like stated before me, hit the backside of that pully with some wd40 on the shaft area-since you cant really get it inside that bearing, and it should quiet down for a day...or an hour. Or loosen the belt while its cold, and turn the pully by hand. it should spin freely. If it sounds like an old scratchy record (round vynal things once used for sound recording and playback that came in various sizes-not to be confused with lazer discs or CDs) then you got a bad one.

run down to the friendly jeep place an get a new one- comes complete with the pully/drum- just unbolt and replace. I think mine was $9. I never checked anything aftermarket-they might carry it by now though.

I got a replacement bearing at the local carquest for about 8 bucks.

The pully with a bearing was $33.

This is in Canada though.

I replaced that and my water pump and I still have a squeaking up front somewhere, I'm starting to suspect the steering pump, but I guess it could be anything.

I hunted down a "supercharger noise" on my YJ for a while before I deemed neither the idler pulleys, water pump, or power steering pump the culprit (though all did make their own distinctive noises once I removed the belt). Ultimately, it turned out that my exhaust manifold had three cracks in it.

I also noticed the noise as the outside temperature dropped, so I attributed it to the thermal differences between a hot and cold manifold.

Just something else to consider.

My AC system doesn't work(as far as I know) perty sure it just needs a recharge.

My Grand Wagoneer made this horrible squealing noise like you describe but that's a TOTALLY different monster, it was from the AC compressor area so I did put some WD-40 on it and that kept it quiet for a few seconds...does your's get louder or start when you hit the throttle? Also when you know it's going to happen and you stay light on the gas does that help?

Yea it goes right along with the rpm then stops and then does its pretty random but when it does make the noise it houls louder and hi-er pitch with the rpm. I'll check the idler pully but its very cold out tonight so it will have to wait till tommorow.
-Steve D.

If you do not have enough refrigerant in the AC system, the compressor will not turn on.

I've been getting that same problem, ever since i replaced my serp. belt. it is properly tensioned, but one thing i've noticed is that when its wet outside, it screaches, but when its dry outside its quiet.

Word to the wise guys, if your A/C system needs a "recharge", then you have a leak somewhere. They are sealed systems that come with the right amount so if its low its got a leak and recharging it ain't gonna do anything. It will just leak out again.

What would need to be removed if i wanna ditch the system... and what would most likly be the culprit for the leak, any easy way to determine this?
Thanks for the help guys
-Steve D

Only way to find leak is to use dye or a leak finder (beeps when it detects refrigerant). This is probably gonna be a dealer/shop thing. Front compressor seals are know to go. If you wanna remove it you are gonna need to have a shop or certified person remove the refrigerant.