Well was going to pikesville md tues nite for MD state police orientation when i heard was sounded like a tapping. so i turned radio off and sure enough there it was! WTF! my first two thoughts were it almosts sounds like an exhaust manifold leak or a valve tap. well i had a buddy of mine listen to it and he says that i need to adjust/tighten the valve lashing. Anyone have any experience with this? iv never done it before . thanks