'01 Drivebelt Squeal Diagnosis Help

[wilmsas]

Hello all,

I've been a long-time lurker, but today I'm posting due to my short time.

The truck is an 2001 XJ with roughly 185k on it. The entire front end has been replaced (Synergy ball joints, V8 tierod ends and drag link, adjustable trackbar, quick discos) as of last week with a good alignment.

I've noticed a loud squeal when the truck was in cruise on the highway and accelerating. I replicated the noise without cruise control finding it to consistently squeal when accelerating from 65MPH to higher MPH and when the Jeep was in between 2500 RPMs up to 3200RPM.

Essentially, when there is heavy load (almost exclusively on highways) it squeals heavily when it shifts down to 2nd from 3rd and will stop when it shifts back into 3rd or when I take my foot off the accelerator. As most of my travel was on town streets at college, it was not a real issue.

I travel roughly 1700 miles to go from home to my college, and today on my way out, I noticed the squealing was louder than before. With the AC on, the squealing was very minimal when accelerating, if at all. With the AC off, it resumes squealing.

When we first had the truck, the A/C was having issues so we replaced all the o-rings, along with recharging it (bought a kit) and putting new refrigerant in. The A/C was working for several months and then stopped blowing cold air. We took it to a shop to see if they could find anything that we might've missed. They performed a UV test and could not find any leaks for the 1.5 days they had it in. They said it was empty of refrigerant. They recharged it and it is still blowing cold. I did notice it getting warmer and losing blowing power today, but after I turned it off for awhile, and turned it back on, it was fine.

Looking through forums, I have concluded that it might be the compressor, the clutch, or even the bearing. Perhaps the serpentine belt itself?

I am in a bit of a time crunch, but what is the most reasonable course of action here? I will take the belt off tomorrow to test the individual pulleys and will report on what I find.

 

[Dragonlich1961]

sounds like multible problems. the squeal and the lossing refrigerant are to seperate probelms. the compresses could be going. my sister had one on her ranger that made a horible noise, not a squeal when turned on. worked for a month, then the comp seivezed on her, and in doing so tryed to smoke the belt. i had an idler on mine that made the most annoying bearing chirp, more pronouced when cold. could aslo see if the belt is glazed.

loosing refrigerant means there is a leak, its supost to be a sealed system, normally good for the life of the vehicle. mine had either a leaking condensor or a leaking line to the condensor. all three were replaced at once since they had become one. two places most places can't get a good look at is between the condensor and rad, and the evaporator. second is no small task, dash must be dismantled partly to replace.

through some dye in the system and runn it for a few days, then go out at night with a black light and look for the glow. best of luck.

 

[wilmsas]

Thanks for the quick reply!

They might be separate problems, but there does not appear to be any leaks right now. The shop put in the UV dye and reported no signs of a leak. This was as of 4 days ago. I'll go and see if I can find anything with my personal blacklight soon.