My 01 150 SC w/a 5.4 and 130k mi is making a clicking noise when I first start out. It usually happens when cold and subsides as it gets warm. It also only happens when it's under load (moving) and is RPM dependant not speed dependant.
I'm gonna check for exhaust leaks but am lost after that. Had initially thought lifters but it only happens when cold and under load - it won't do it if it's sitting still - makes it really hard to pinpoint
Not pinging. took a ride on the running board w/the wife driving (don't try this at home kids). sounds like an exhaust leak. couldn't see any cracks in the manifold. thinking maybe the doughnut went bad at the connection between the manifold and pipe.