My brother-in-law overheated our '91 XJ at around 195K miles. A leaky bypass hose causing loss of coolant and the radiator to melt.

 

Now at 205K miles, I hear a whistling noise from the engine bay that changes pitch with engine speed. The engine idles and performs normally. I suspected the water pump was going south and took off the belt to confirm to also find a tiny bit of in & out play in the water pump pulley.

 

Does this confirm my suspicions?

 

Any other thoughts?

Might be, Usually they leak out the bottom of the pump on the inline 6 when they go out. Good news is it's easy to replace and costs very little.

 

Could your alternator be going out? The whining is common with those.

Also easy to replace. Love that about Jeeps.

Remove all the drive belts and see if the noise goes away.

 

200,000 miles is a lot of mileage for a water pump on any car, but usually they leak first. I would suspect the ALT bearing or any idler/tensioner bearings on the drive belts (if any).

 

 

nipper