details: 99 XJ, 4.0 6 cyl.

Recently I've started to hear a kind of "ringing" / "tinging" sound from under the hood at idle. Could be doing at speed as well but engine/road noise may just be masking it.
Using my mechanic's stethoscope I started poking around thinking that it could be a bearing starting to go bad. Most of them that I checked are fairly quiet... for a 20 yr old jeep with 100k on it.
When I got to the fan clutch shaft I listened just on the edge of the housing and the bearing didn't sound trashed to me, but I could start to hear the "tinging' sound a bit.
So what I'm asking here for is... is this normal? or is this a sign of something starting pack its bags to head south?
Also, I don't think there's any play in the fan clutch itself. I will recheck that, but don't think there is.
I'm just trying to be proactive on this one so any info would be greatly appreciated. Thanks....

 

id check your pulleys for noises

 

I have had this when my AC lines moved forward a tiny bit. I think it happened when I was movving the battery around. they came forward just a little bit and then the fan would touch them occasionally. Made a very faint tinging osund like you described.

 

I put the scope on everything that has a bearing under the hood. The first thing I thought it would be before I actually scoped it was an idler pulley. But it didn't sound trashed and the "tinging" was coming from the the other side of the engine bay. The only thing I put the scope on that had that sound was the edge of the casting for the fan clutch assembly.
Other bearings sounded worn, but not trashed.


I don't think anything physically shifted, my battery is pretty locked down. There's nothing coming into contact with my fan physically that I can see.

 

If the sound gets a little louder/more clunky sounding,,take off the serp belt and check/feel the water pump..At 225k I have replaced the water pump twice..Just don't want it failing 100 miles from home.. HTH WAYNE.

 

Just replaced mine about 6 months ago... but on a Jeep anything's possible. lol.