Has anybody ever experienced or know someone that has had their rocker arms come loose? Is this possible? I haven't cracked the motor open to take a look at it but i can clearly feel that there is a very strong knocking in the head and it is very loud! What should be the first thing i check out once i take the valve cover off? I've already confirmed that there are no metal shavings in the oil.

 

Bump...anybody? Any opinions?