ok this is where your going to have to bear with me. This deep in the engine i'm not sure about everything. I've been told by the guy that helps me work on my car that this could be a warped or cracked head, valves, piston ring, and he agreed about the piston skirt. Now if i rent this borescope what am i looking for in they cylinder. Cuz i would much rather not replace anything i don't need to. How can i tell which one of these problems is the one i have.