I recently got a new motor and with that a new serpentine belt. When I start it up and turn the a/c on it squeels like crazy until it warms up. Is it a new belt wear in or is my compressor going bad?

 

Your belt is too loose. Mine did the same thing when I bought it. You want a Dayco Krikit or something
Check this thread for tension. I usually crank mine to about 180 when new. Once it stretches out it sits at about 145 and no squeals.

Seriously, the tension gauge makes this job a 5 minute no brainer. Spend the $15 bucks and watch the video.

 

And:



Best belt I've ever used. Well worth the money.

 

Agreed!

 

If tightening or a different belt doesnt help it could be the fan clutch. I would definitely recommend an electric fan swap.

 

Mine squeals like a pig with out the air on I put a new belt on but it still squeals so I should just tighten my belt to then

 

On the 4.0's the electrical fan and the mechanical fan work together you should have both really as the working pair does an excellent job of cooling. Only thing I run electric fans only on are race cars and very high HP ones that use an electric water pump also.

 

Thank you all for the advice. Krikit gauge getting ordered today.

 

I actually just came across this issue myself. My Krikit gauge came in today but by time I woke up to use it it was dark out(I work nights so weird sleep schedule) So tomorrow I'm going to get out there and try it out and possibly have to tighten my belt. Hopefully the belts just too loose and needs to be tightened. Otherwise I will have no idea since I replaced my water pump a couple months back and my idler pulley about a week ago.

 

The serpentine belt has to be ridiculously tight or it will squeal every time. Using a Krikit is the only way to tighten the belt enough but not so much that it chews up all the bearings in the accessories.

 

That's what I have heard lately. So tomorrow first thing ima get out and tighten it up! Thanks.

 

SO I found out why I haven't been able to tighten the belt on my 1990 XJ. The bolt that I am supposed to tighten has a housing unit around it to tighten it and unit has been broke...I have no idea for how long I just noticed that the bolt was wiggley and not tightening so I pulled at it and sure enough it came sliding right out and the unit crumbled after pulling the bolt out. F me. Is it safe to drive with that broken? This is my DD so I am boned if this has screwed me over....Also sorry if this is the wrong place to put this....

 

If I recall correctly, the adjustment is on the alternator. So you should be able to throw some rope around the alternator and pull it to the side to give you enough tension to turn everything (powersteering, fan, alternator, etc), then head down the Junkyard and pull a new bracket to replace the broken one. If you can't get some tension on that belt you will overheat in less than 5 minutes, and you will have NO power steering. (Ask me how I know!)

 

There is tension on the belt. Roughly the same amount that has been there so I think I should be safe to drive around just no wheelin to be safe. I tried looking up "tension-er bolt housing and other stuff" but nothing popped up so idk the name of what I am looking for exactly

 

Hit the junkyard. You'll find one.