Hello everyone, this is my first post on here although I've read a lot and learned a whole lot more!

I have a problem... My XJ has developed a knocking noise and I cannot tell if it's the infamous flex plate or if it's an engine knock. This is a link to a video I posted on YouTube of the sound: any help would be awesome! I just bought the jeep about 3 weeks ago and It has 223,000 miles on it and it's a 1996 4.0

Also the CEL is on and I took it in to autozone and it said O2 sensor and 4th cyl misfire. so I went ahead and replaced both upstream and downstream sensors and I reset the light and it came back on. What causes one cylinder to misfire?

Thank y'all in advance!

 

I'm gonna provide 2 things for you to look at.


Straightshooterjeeps cracked flexplate diagnosis

I removed 3 of the 4 bolts.

Then loosened the last bolt about half way.... I left this one in to maintain connection between the tq and the plate. Just so I wouln't have to fiddle with putting bolts back in too much.

Now the flexplate is pretty much seperate from the torque converter.

Got my flashlight pointed up in there

Grabbed a big flathead screwdriver and started prying on the flexplate

Don't see anything yet

Turn the flexplate a half rotation

Pry again

and there it is! A big fat crack up near the center of the plate.

When the flexplate is loose from the torque converter you can get it to "flex" real good and you just might be able to spot your crack.

Just to be sure you do have one before dissasembly.

It was very obvious at this point, but before pulling those bolts I looked and looked and could never see a crack.

Hope this helps save someone a little time.


https://www.cherokeeforum.com/f51/ho...ocking-125547/