Hello All-

97 Cherokee XJ. 4.0-
I've been having noise from what seems like one of the accessories on the serpentine belt; I assume it's a bearing or something like that. Today I changed my Thermostat and went ahead and took off the serpentine belt and ran the car to see if the noise went away. The noise did go away which confirms it's something on the serpentine. While I had the serpentine belt off, I hand checked all the Accessories for looseness or making excess noise when spinning; Couldn't figure out where it was coming from. It seems to be coming from the left side where the AC compressor, fan, and alternator are located. The sound is a a knocking sound which you can hear for about two seconds then goes silent two seconds and it continuously goes on.

Any insight would be appreciated. I'm trying to get ahead of this before it puts me on the side of the road.

Thanks,

 

I had that type of noise, and it turned out to be the water pump. I just let it make noise, not knowing what it was, until the pump bearing failed..