Originally Posted by camoed90XJ

well I have had to work on a customer jeep and he was complaining about a tick, that gets worse as it gets cold. could definitely tell it was coming from the top end, which leaves valve train to be suspected. there are a couple different TSBs available for these types of noises. one in particular stuck out in my head. the line boring on the block for the cam was done wrong and the cam was allowed to move back and forth hitting the timing cover which had a possible fix of putting a new cam bolt in. the other fix which is what i did to this jeep was a valve rotation. although this is mostly associated with a misfire problem it can cause a noise. the 4.0 causes so much carbon build up that the valve get large deposits and can no longer rotate the will eventually start to stick, its as simple as removing the valve cover and inspecting the tappet it should have a round wear mark on the top of it indicating the valve is spinning if it doesn't a valve rotation should be done. i believe there was also another TSB involving the distributor and how it picks up its timing causing noise. a mechanics stethoscope becomes very handy looking for these noises.

Originally Posted by Slick761

What do you mean by doing a valve rotation and how do you look at the tappit by just removing the valve cover.... Hey also does anyone know if there's a roller cam conversion for these engines?

Originally Posted by camoed90XJ

the valves need to be spun 90 degrees. sorry also have to remove rocker arms. its not the tappet since its a push rod motor that was my mistake. its the actual valve stem. circular wear pattern indicates a spinning valve. i am assuming you mean roller rockers multiple companies make them. have no experience with any of them therefore have to opinion or suggestions to make, just google it