[cherokeechico]

i hae a 2000 xj and when it gets cold out (winter time) the engine squeaks like a slaughter pig, i will floor it and hit 35-40 mph and then it will stop and i smell something funny. it also squeals when i put the defroster on at anytime, i can put it in netural and rev it a fewtimes and sometimes it stops sometimes it dosent. my jeep dealer replaced th serpitine belt before the squeaking ever started. ive tried putting STP belt lube on the serpitine belt and tighting the bolt by the pwer stearing but i am reluctent to tighten it too mc because i dont want to warp the bearing in the pully. its a real annoying sound and people look at my jeep for the wrong reasons, please help

[MJR]

Originally Posted by cherokeechico

i hae a 2000 xj and when it gets cold out (winter time) the engine squeaks like a slaughter pig, i will floor it and hit 35-40 mph and then it will stop and i smell something funny. it also squeals when i put the defroster on at anytime, i can put it in netural and rev it a fewtimes and sometimes it stops sometimes it dosent. my jeep dealer replaced th serpitine belt before the squeaking ever started. ive tried putting STP belt lube on the serpitine belt and tighting the bolt by the pwer stearing but i am reluctent to tighten it too mc because i dont want to warp the bearing in the pully. its a real annoying sound and people look at my jeep for the wrong reasons, please help

This is usually due to a loose or worn belt. The 4.0L ones need to be a little tighter than most.

[MaDAssassin]

I cleaned my engine with some simple green and a little water and that stopped that, i focused on my belt..

[1stJeepXJ]

On the 2000 XJ, you must tighten the tensioner, usually a couple or three week after it is initially installed to compensate for the slight stretching that it does. You should check the tension periodically after this. This is NOT an auto-tensioning idler. Do not use belt dressing, a lazy, temporary, nasty fix in my opinion. If you are smelling your serpentine belt smoking, I would no longer trust it and get a new one. A smoking belt gets extrememly hot, too hot. The reason you squeal with ac or ac in defrost is due the added load of the compressor. Flooring this vehicle to get the squeal to stop is similar to sitting from a stop and smoking the tires, not good on rubber compounds. Hope this helps, good-luck. Oh! to tighten this belt, you must loosen the bolt holding the idler pulley to the bracket. Do not remove this bolt, just loosen it. Belt tension is then adjusted from the bolt to the top and left of the pulley. If you are looking down on this pulley, the adjuster bolt will face up at you. Dont forget to re-tighten the pulley.

[cmassey_2001]

Originally Posted by cherokeechico

i hae a 2000 xj and when it gets cold out (winter time) the engine squeaks like a slaughter pig, i will floor it and hit 35-40 mph and then it will stop and i smell something funny. it also squeals when i put the defroster on at anytime, i can put it in netural and rev it a fewtimes and sometimes it stops sometimes it dosent. my jeep dealer replaced th serpitine belt before the squeaking ever started. ive tried putting STP belt lube on the serpitine belt and tighting the bolt by the pwer stearing but i am reluctent to tighten it too mc because i dont want to warp the bearing in the pully. its a real annoying sound and people look at my jeep for the wrong reasons, please help

Yeah, I think this is a common problem with all 4.0 L engine models. My previous '96 xj did the same thing and now my current '98 xj is doing it too. I've tried tightening the belt, but that was only a temporary fix. I've adapted to this problem by not turning the ac or defrost on until I reach speeds of 30+. Just leave it on vent mode when you first start your car. Once you get going at speeds of 30+ mph, then switch it to ac or defrost mode and it won't squeal. I think I'll try what the other peeps are saying here first to see if it fixes it. But until then, I've used that simple method of getting around the noise.

PS: I replaced my belt and it still does that slipping sqealing noise.

good luck!

If you find a solution to this let me know!