From about 1000-2000 RPM, There is this loud consistant "clacking" under the valve covers, and the occasional rough idle. There is no engine pinging. Injectors are good. (FORD sent out a service bulletin on injectors in the 05' 5.4L) I've read and heard that it's natural for the Triton. No "check engine" light. A couple times I have had hard hot starting, but not cold. This noise can't be natural when it gets louder over time. CAN ANYONE TELL ME WHAT THIS IS?! Rocker arms? Lash adjusters? Please Help!

 

Follow this link
And watch episode 22 on the Variable Camshaft Timing.
IIRC it goes over the noise that is made if your cam phasers are not operating properly. I believe their is a TSB on that but I am not sure, hopefully someone will chime in.

 

Remove the 5.4 Triton badges and replace them with PSD emblems!

Just kidding - I'm in a sarcastic mood today........