My rubicon started knocking and it is consistent with rpm range. It doesn’t get quite when cold or louder when hot. After taking valve covers off I noticed there was 1/16 to an inch gap in valve adjustment with the greatest being on the exhaust side. I removed the powerhead and noticed the intake valves and been making contact with piston. I can hand crank the engine and everything in lower end sounds good and is getting adequate oil. Has anyone seen this before? Should I do a valve job and try it?