I have been hearing a rattle in my 91 Jeep Cherokee for a while now. I thought it was in the exhaust at first. But as it got louder, it was clear it was coming from the front of the engine.
I pulled off the idler pulley but the bearings in it were fine. I replaced it and reset the belt tension. The noise as defiantly coming from the front of the engine.
I got my mechanics stethoscope and began listening. The noise seemed to be the loudest at the water pump. I have never had a water pump bearing fail with out it leaking first. But that sure seemed to be the case this time.
I tried to ignore it for a day but the noise just got worse. I stopped by Autozone and verified that I had a warranty on this part that I had replaced in 2007 according to their record. I picked up a new pump and some antifreeze.
I was still skeptical but when I removed the belt and turned the pump by hand I could feel the bad bearing. I removed the pump using the procedure I have practiced way to many times.
I put the old pump in the vise and the noise was very clear when the pump was rotated.
I installed the new water pump and refilled the radiator. I found leaving the heater hose off the water pump allowed the air to bleed quickly.
Once I started it up it ran nice an quiet. The only casualty was that I broke by fan shroud while moving it around to get to one of the bolts. I will have to fix that before summer.
I took the old water pump back to Autozone this morning and got my money back. It was a very simple exchange. They had all the info in their computer.
If you want to get a 4% rebate on purchases from Autozone, use this link to buy online and pick up at the store. http://tinyurl.com/6fpp7se