86 cj7 Loud squeal when idlng

bgrinder

New member
I have an 86 cj7 with 4.2 inline 6. California model ( Lots of vac. lines) I just started getting a very loud squealing sound . only when idling or low rpm. Goes away when driving. Any ideas?
 

I have an 86 cj7 with 4.2 inline 6. California model ( Lots of vac. lines) I just started getting a very loud squealing sound . only when idling or low rpm. Goes away when driving. Any ideas?

I have a 2001 wrangler, and all of a sudden, I started getting a high pitch whine/squealing that I was able to track to my pulleys. I ended up putting a bunch of silicone spray on them, and the issue went away, hasn't come back since.
 
I used to have a 1990 cherokee with a 4.0 that was prone to squealing. The silicone spray was only temporary on mine. Replacing the serpentine belt would stop the squeal. I found that the better belts went longer before the squealing returned than the lower priced ones.
 
As stated it is probably a belt squealing. Check the tension on the belts. A loose belt will slip at low RPMs causing a squeal, as the RPMs increase the squeal will often go away. Also if any mods were done that affect the pulleys(different alternator, power steering pump etc.)make sure the pulleys are straight & perfectly inline. If all else fails some spray-on belt dressing may be needed.
 

and, to help pin point, hold a bar of soap on the underside and top of belts to see if squealing goes away on serpentine belts, or just underside, on v-belts
 
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