ok my jeep started making this noise and im not sure what it is http://www.youtube.com/watch?v=GRYrx...e=related(this is not my jeep but it makes the exact same nise ,will post one of mine ,buddy said it could be lifter
93 Cherokee 188km

 

It is a lifter if you hit the gas it stops mine is the same way 94 with 300,000 on it so your good man

 

sounds like the engine knock that alot of 4.0's are nown for. my old 96 did that. ive seen engines with 250k plus goin strong doin that. maybe it got louder because u have a manifold leak? whatever it is i think youll be fine

 

My 96 xj developed the same sound, dropped oil pan and found #6 piston missing its skirt. Installed new piston noise gone.

 

heres the video took it with my cell so kinda ****ty

 

well changed the oil and added sea foam has made the noise less noticeable going to drive it for a week or two and go from their .