Im having a few problems and was wondering if anyone had experienced them also and has any suggestions for me.

The serp belt is squeaky as hell on cold days start up. However, it goes away after about 30 seconds of driving, and will come back sometimes and then go away again quickly. It doesnt stop if i have the heater fan turned up and goes away quicker the lower the setting its on. Its not too tight or too loose. The only thing I have so far is maybe a bad pulley? The PS pulley seemed to spin a little rough...

Also, I believe I have a vac leak as there is a very high pitched noise that comes up as the jeep warms up. Im pretty sure its a vac leak as it subisdes when i apply the throttle. It also will come and go...

Any help or suggestions would be great. Thanks.

 

Pop the hood and have someone start the engine while listen for the source of the squeal. A/C compressor pulley bearing, and tensioner pulley bearing are common sources.

 

Sometimes the pulleys get glazed from the belt being run loose. Instead of buying new pulleys I just de-glaze them with an aggressive bead blasting or sand blasting.

 

Get a dowel rod or cut off a broom handle. With engine running and squealing, put the pole against your ear and carefully probe the other end around until you locate the source. I've done this to diagnose both a worn idle pulley and a worn distributor.

 

I think the squeal is the idler pulley but it spun fine. I listened for the noise and it sounds like thats where its coming from.


Any ideas on the vac leak?

 

I'm going to replace the pulley this weekend and maybe the PS pulley and see what that does. Its weird because it only squeals when its really cold out on start up.

Thanks for the help, and vac leak ideas?

 

Go to the tech. write-ups, you might find something worth reading....

 

nice write up! I'll try it.

 

My wife's 1996 Grand Cherokee 4.0L with 113K miles just crossed over from intermittent squeaking when cold at startup to squeaking half the time.

After I couldn't localize the noise to the alternator, power steering pump, idler pulley, etc. usual suspects, I bought a Mechanics' Stethoscope at NAPA. The noise was seemed louder on the passenger side of the engine. This week it was consistently bad, so I took off the serpentine belt - it still squeaked! Without all the fan, alternator, PS pump noise to mask the squeak source, it was really clear it was coming from the passenger side of the motor. Touching the stethoscope's probe rod to different parts of the head and block, the distributor soon revealed itself as the source of the noise.

Several years ago, when engine squeaking and squealing were seriously annoying the wife, the culprit was the water pump (bad bearings).

As for my current noise problem, removing the cap and rotor brought a big surprise. The upper bushing holding the distributor shaft is severely worn. A piece of .035" MIG welding wire will pass between the distributor shaft and the worn upper distributor shaft bushing. It's amazing the engine runs, let alone runs very well. Time for a new distributor.

If yours is anything like my wife's, it will have quiet days and noisy days. When a noisy day comes along, drop everything else and dig into it. If you can localize the noise to passenger or driver side, your half-way there. The Mechanics' Stethoscope is a big help pinpointing the noise source.

Good luck.

 

Do you run the heat on Defrost, the A/C compressor will run on defrost. You could also try some belt dressing which can be picked up at any parts store, if your belt is old it will dry out and the belt dressing will make it more tacky and stop squeeling.

 

Mine is a 2000 so no dizzy, but thanks for the great reply! I really hope its not the water pump... I dont know how hard they are on Jeeps but the ones that I've done in the past have been a PITA.

As for the reply from Wahoo, the belt is actually pretty new. Its not cracked or worn at all. I tightened it even more and the squealing as gone down some but its still just so weird how I can watch the volt gauge climb to 14 and when it hits 14 the squealing stops. When it drops below 14, like when I turn the blower fan on high, it starts to squeal again. But its not my alternator becasue the noise isnt coming from it, and the alternator is charging just fine...

 

I don't know about a 2000, but replacing the water pump on a 90 or 91 XJ is a piece of cake!

Be carefull putting excessive tension on the belt because too much tension can cause problems with the bearings in the alt., A/C, water pump, P/S pump Ect.

I have fixed many customers cars and trucks (as well as my own) by
de-glazing the pullys by sand blasting them. It's a simple fix and allowes the belt to grip the pully and it will last for many years as long as you have a good properly adjusted drive belt.

 

X2^^^

A very wise, older gentleman mechanic once suggested using a piece of 1/4" vinyl hose to chase down the squeal.

Either way, pinpointing the source is your first step.

X2 on taking care not to over-tighten the belt, too!!

 

well I'm pretty sure its my power steering pulley. I used the trick of putting an extension on my ear and tracking it down. Just doesn't make sense with the volt gauge I guess.

 

I dont think I made it too tight. Theres about a 1/4 in'' of slack by the AC compressor. Serp belts are supposed to run fairly tight anyway.