something definately is screwed up in there. you'd be surprised what it could be. i bought a jeep for 200 bucks one time cuz it sounded like that. come to find out he had sludge build up cuz of the lack of oil changes on time. its also from the lack of oil pressure. the push rod heated up so bad that it literally burned a hole through one of the rocker arms.

i'm assuming that in the chat they told you to check ur oil and u did and its good? lol