Rattling noise when at idle. I Have heard the sound for a few months now but still not sure what it is. I have a 93 and shes auto. I notice the rattle quiet down with every oil change but then it sneaks back into my life.
Sounds as though it comes from lower central engine (almost near oil pan)
No oil leaks so I'm not too sure what the deal is here. Replaced the serpentine belt but that didn't solve the noise issue. I dont wanna turn up the music and ignore it any longer... Any ideas?

Thanks guys

 

Rod bearings. Drop the pan and check them, its not that hard to drop the pan

 

Home made stethoscope - take a long thin bar of some sort (long socket extensions work best, really long though) and with the motor running, place one end on a metal part of the motor or oil pan, and cuff the other in your ear. It'll amplify any sound inside, then you can get a better idea of the general area of concern.

+1 to dropping the pan.

 

3 foot pc of rubber hose works also

 

you mean robble robble robble??? haha southpark anyone? could be exhaust. check all of your hangers. seems like all of my vehicles have had this problem at one time or another.. just my two pennys

 

oh and the jeep i just bought (98) has the same problem, exhaust rattles against the frame cause the hangars have rusted and broke loose

 

another thing to check for is loose torque converter bolts. You can remove the inspection cover on the lower part of the bell housing and check to make sure they are tight. you have to turn the motor over my hand to check all 4

 

I had significant noise from the guts of the cat converter shaking about, the noise usually was loudest just when you got to the coffee drive thru, gone now, really though it was intermittent based on where the internal debris was jammed at any given time. Check your cat and exhaust. My current rattles and roars are from the cracks in my exhaust manifold.

 

x2 + .02 cents

 

I had a very similar noise. I thought it was rod bearing but after some more checking I found it was my water pump. Remove your belt and see if you have any play in the pulley and if it turns smooth.

 

I had a similar issue with my flex plate bolts being loose, worth checking those while you are looking around.

 

Looks like I need a day off to do a nice checklist on it... Haha seems like it can be a number of things. I have new hangers and aftermarket muffler and it isn't that area that the sound is coming from either. I did have a crazy rattle from the cat piping rubbing on the xcase skid which I fixed... This is a different noise tho. x2 on the tim hortons drive thru haha that was brutal... but that was right before I fixed my exhaust all up. I don't have any unusual amount of play in my belt. I'm really thinking it is loose flex plate bolts... Here is a video that sounds exactly the same.. even same muffler :P
Thanks for the tip Jerm and Fscher.. Hopefully she will be good to go tomorrow!

 

Anyone know the torque stats for these bolts on the flex plate??
My Haynes repair manual is with another XJ owner at the moment
Someone save the day for me!

 

Oh ya sorry here was the video for my previous comment

 

When I did my bolts, I just snugged them up the best I could. Make sure to disconnect the battery so you do not accidentally start the jeep when you are spinning the flywheel to access each bolt. That is what I have been told, i am a novice when it comes to doing it myself. You will have to have two people to do it, one person to hold the flywheel in place while you tighten it. I apologize, I am not sure what the part is called that you need to put the socket on to prevent it from spinning.

Hope that helps a bit more lol.