I have a 96 cherokee, Now there's a lot of tapping coming from the valve cover area near the front I just replaced the lifers and rocker arms i took the push rods out and ade sure there not clogged as well as rolled them on a table to make sure they were not bent. and there is still tapping. I don't know where else to look. Can the tapping come from the worn out tips on the push rods? Or can something else be causing this? I just want to know were i should check before i replace the push rods.