My 93 XJ ticks at start up, I'm thinking its probably lifter or valve. Its sounds a little less muffled if I take oil cap off is why I think this. I have the 4.0 HO I6.
Am I looking in the right place? Also should I replace everything on the head while I'm in there? And is there a kit that I can buy that has all the lifter, rods, etc in it so I don't have to buy it piece by piece? I haven't opened the valve cover and actually looked because this is my only vehicle in the house hold. It also speeds up with rpm.

 

I added 1/3 bottle of Seafoam to the engine oil about 100 miles before changing oil.
Seemed to clear up the problem after a coupla oil changes/

 

marvels mystery (spelling?) fluid its in a red bottle at any local parts store it sounds like you have some varnish on your lifters this stuff should make your tick go away with in 30 minuets of poring it in

 

Mine only sound loud when I go thru a fast food drive thru, the noise bounces off the brick wall of the building and is easy to hear.

 

ok Ill try the M.M. Ill be able to find it easier probably.