Engine Problems....
 

To make a long story short, a few months ago i drove the car and the oil cooler was leaking so i kept topping up oil and to drive it home, then this loud weird fluttering sound came on. So we fixed the oil cooler now, no leaks and still drives with power. but my question what is really wrong with the loud noise only at high rpm, its sounds horrible....u cant even hear it when idle or at low rpm but sounds like a diesel car......please help if any mechanics out there now this issue ( was told so many things but mainly either bearing in the lower block or/and some kind of chain)