I have 96 XJ 4.0 with 160k and have this tap/knock I can't hear it above 2000 RPM and can only really hear it at idle in park and it's quite in gear but i can still here it, and it is always there engine cold or warm i can hear it also I my oil psi is 40-50 at idle and 60 on highway. Is this lifter tap or piston slap here's the noise
https://youtu.be/nFt-65jPX68

 

I have a 96 XJ 4.0 with 160K and I can hear this tap/knock and I'm not sure what it is I can't hear it above 2000 RPM and can only really hear it at idle in park and it's quite in gear but i can still here it, and it is always there engine cold or warm i can hear it, also I my oil psi is 40-50 at idle and 60 on highway. Is it lifter tap ,piston slap, or flex plate what do you guys think? here's the sound i bring it around 2 grand and go from park to gear to show you what im talking about
https://youtu.be/nFt-65jPX68

 

I've never heard a wood stove make those noises before...

All kidding aside, it's a tap. Your flexplate bolts should be checked for looseness. Here's how:

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

 

I ended up finding that same thread a while back and figured I could check I got under my Cherokee and noticed the bell housing cover was gone and I felt the bolts and I was able to take them out with my fingers so they where so loose, got them all tightened, went to local jy for that cover put all back together, and started her up and she sounded great no knocking no ticking just the pretty purrr of that 4.0

 

Yay, Pretty easy fix.......