Hi Everyone,
I have a noise that I can't locate on my 01 4wd with the 4.0. It has 130,000 miles. It sounds like a pulley bearing is going. Kind of a mild rubbing noise like a bearing is failing. It doesn't change when I turn the wheel or when I turn on the a/c. I pulled off the belt last night put on a new belt and checked all of the pulleys. Everything felt smooth and didn't make noise when I spun them. Only thing I noticed was that I couldn't turn the A/C compressor by hand and the power steering pulley has some slack inside the pump when I turn the pulley back and forth in the same direction it would turn with the belt. The noise sounds just as loud when sitting in the jeep with it running as it does looking under the hood. With the fan turning I just can't identify the exact location. Water pump isn't leaking and feels good. Any suggestions?

Thanks,
Tim

 

Use a piece of rubber hose as a stethoscope. While the engine is running, put the hose close to each component that is turning.

I would start with the idler pulley first.

Be REAL careful.

 

Visually inspect the crankshaft damper and see if it's rubbing on the timing chain cover. See if the rubber in the damper is extruding.

You should have been able to turn the AC compressor clutch freely when it's not engaged.

You can remove the serpentine belt and run the engine (for a moment) to isolate all the accessory drives.