Ok so i have this noise coming from my engine. Kind of a tak tak tak. Thought it was an exhaust leak at first but it was gone next time i started my jeep. Didnt do it for couple of days then today i cranked her up and there it was tak tak tak. I listened to it for a min and gave it some gas it speed up with the rpms just for a sec then it stopped. Sounds like maybe a lifter collapsing to me. She only has 87,000 miles. Any body have any ideas or input, Is this a common thing for jeeps??