I'm kinda stumped atm on this one. Searching online, shows everyone from Ford truck guys to other modern V8 Ford engines having the issue or saying they have an issue and it sounds similar with how they describe it. On mine, if it sits awhile (like overnight) upon starting, it makes a racket for about a second. Like either the timing chain hydraulic tensioner is collapsed and is allowing slack for a brief moment before priming up, or possibly something is amiss with the oil filter (dunno if these run an anti drainback valve or not?). After running, and any subsequent start ups within a reasonable amount of time, it sounds like a normal engine at start up. It idles fine, revs in neutral fine, etc.. But upon sitting and starting, it'll make a racket.