Belt noise

[Johnfromphilly]

Newbie here still learning with my 2001 TJ.

This noise just started happening. It comes and goes and gets louder and softer. I am guessing this noise is from the belt. How do I diagnose and fix this? Is something loose and just needs adjustment?

ignore the lifter knock. I was told to do the same. Haha


Thanks for any help!!

 

[5632]

Give the serpentine belt a quick shot of WD40 and if the sound stops for a few seconds change the belt.

 

[RMETeeJay]

What condition is your belt in? When was it last replaced?

If the belt is good, it's most likely a tensioner or idler pulley bearing failing. Remove the belt and spin both by hand. There should be no binding or play/slop.

For the tensioner, you can replace only the pulley/bearing and re-use the rest.

 

[Brianj5600]

A friend of mine that repairs cars swears by Gates belts to quieten front dress. A Gates belt quietened down both my Suburban and TJ front dress. I stashed the noisy belt in the vehicles just in case of a belt failure.

 

[Jerry Bransford]

One thing about serpentine belts, they can look bad to the uneducated eye. Small cracks going from side to side across the belt are absolutely normal and they can form very soon after the belt was first installed. The cracks that indicate impending failure run lengthwise.

But as above, I'd first suspect a bad idler pulley. When the bearings go bad it'll start chirping and/or squealing.

 

[AndyG]

You can also squirt water on it and if that quietens it It is the belt most likely...

If it has ever been saturated with coolant that typically does one in

The tensioner pulley is also suspect where it rotates around the bolt so a little WD-40 will tell you that needs replaced it’s very cheap

 

[Johnfromphilly]

Give the serpentine belt a quick shot of WD40 and if the sound stops for a few seconds change the belt.

WD 40 had no impact on the sound. Still the same. It is not constant and it goes away with reviving the engine then will return. or not.

I will read through the thread and take some of the advice and report back.

 

[Johnfromphilly]

What condition is your belt in? When was it last replaced?

If the belt is good, it's most likely a tensioner or idler pulley bearing failing. Remove the belt and spin both by hand. There should be no binding or play/slop.

For the tensioner, you can replace only the pulley/bearing and re-use the rest.

I will give this a try. I need to do some searching for instructions and how to videos of removing the belt etc. have not done that before but I am happy to learn. Thanks

 

[RMETeeJay]

You got this, it’s an easy job. To remove the belt, I use a 1/2” breaker bar. The tensioner is spring loaded. Insert the bar into the 1/2” hole, compress the spring and remove belt.

If you don’t know the age of the belt, now is a good time to replace.

 

[Johnfromphilly]

Once again this forum comes through. I replaced the tension pulley and the idle pulley as well as the belt (probably didn’t need it as it was in good condition but I figured I might as well while it was all apart).

The biggest issue I had was getting how to instructions as the searches kept giving a different setup than I had. I finally found instructions that showed my setup and it was as easy a project as I have done once I understood it. Using a breaker bar to release the tension was the step I was missing. Although @RMETeeJay mentioned it I had no idea where to find the hole and how to do it. I found step by step instructions for that and it is so simple I felt dumb after. I was then very careful to not strip the torx head on the screw, I actually used a plumbing wrench to get it loose then finished with the torx. I was also careful to note the path of the belt as my diagram is worn off.

Once I was set up it took about 20 minutes. Zero sounds from the belt anymore and I took a drive just to be sure nothing came flying off.

Thanks again for the help and encouragement!