Ok still tryin to figure this jeep out. 4.7 which has a loud tickin or tapping sound that grows with acceleration. checked all the rockers and the hydraulic lifters and all seemed fine. is it possible the its the a/c compressor? dont know how many times i listened around with a long screwdriver but alot and always end up at the top of the a/c compressor. i can hear like a knockin at the top of it consistent with the revs and the compressor prolly didnt have any refrigerant in it for a couple years. i realize sound transfer, but dont hear it at lower part of a/c or any surrounding spots that are connected to the block since i figure if it was internal ya should be able to hear somethin maybe even louder or more distinct but nothin. its puzzling me, never would think a/c could make a noise that loud and consistent with engine speed. sounds like very very loud lifters but its not. i had changed motors since last one was bad and even the bad one had this noise along with a spun bearing but put the original a/c unit back on so thats why im leanin towards that. so guess im askin if this is posible?