Driving the van over the weekend and it developed a sudden rattle in the valve cover. Fairly loud/extreme so shut it down and had it towed to a shop. They are disassembling now, but what are common failures in the upper cylinder head on the 5.4L? Broken springs or rockers? Push rod? The odd thing is that the engine was running fine otherwise. I wouldn't have noticed any difference if not for the noise.

Any guesses? I should have confirmation late today or tomorrow. :-(

 

Well it's a sure bet it's not a pushrod on a 5.4 They have been known to blow out the spark plugs

 

Oh yeah... duh.

Still no word from the shop... fingers crossed although they already quoted three hours just to remove the valve cover to diagnose the problem.

 

Check the spark plugs to see if any are loose. Doesn't take money to do that. a blown plug will make a terrible racket

 

Crazy... just got the diagnosis: There's a baffle inside the valve cover fastened by two 6mm bolts. The baffle came loose and was bouncing around in the valvetrain. Fortunately no damage so just reaffix and put it all back together.

At least that explains why the van still ran with no other symptoms other than noise!