it doesnt sound like this, but just to check: if it happens while you turn, or sounds like its predominantly on one side, check your CV joints.

most likely, it sounds like you need to clearance your valves. if its a slight clicking at idle, and increases with RPM, and sounds like its coming from the valve cover/top end, you prob just need to clearance them. its not hard to do, just might be tough on the V6.

GL