I have a 2004 supercrew with the 5.4 v8 and there is a pretty loud rattling noise when it has a cold start. But when the motor is warm it starts up with no rattling at all. When it rattles it gets loud then goes away after a second or two it's strange to me any info is greatly appreciated. Thanks.

 

What are you using for oil and oil filter?

 

Royal purple and a k&n filter

 

What weight RP?

 

I have the same sound on my 06 5.4. Ive been using 5w20 castrol full synthetic and motorcraft fl820s filters. I believe its the timing chain rattling but not 100% sure

 

Rattle or vibration sounds? Could be a busted cam phazer that is moving around? Does your truck "tick" at idle? The tick will go away as you raise the RPM if its the cam phazer

 

its probably just your oil taking a split second to get everywhere. i use mc 5-20 along with mc filters and will get this on occasion when i havent driven it for a while