I have a 2003 F250 and it started making a popping sound over piston 3 passanger side it makes the tubes on top of the rocker cover bounce. Valve problems?
by rocker cover you mean valve cover, yes? And by tubes, you mean the PCV breather hose? If that is moving/popping, clean it out, as well as the PCV elbow and valve. It may be gunked up with emulsified oil. Once that is clean then evaluate engine performance. You can run a leakdown test to check valves and seals, as well as a compression test.