The Jeep engines 2.5 and 4.0 are know for valve train noise as they age. So a couple of things can be done. You can sustitute one quart of oil for atf on your oil change and it will clean up some old residue. Then change again within 500 - 1000 miles and put in quality oil. Others will run some Marvel Mystery oil. There are several brands. Or you can go the other way and replace the push rods and rocker arms clean up the area and put the cover back on oil change and see what happpens.
89YJ 2.5L TBI, AX-5, NP231 SYE, Ford 8.8, Yukon Grizzly, Tom Woods Shaft, 33" BFG T/As, 4" lift, Warn VR10000s.
AF Jeep Club Tail #184