Hello,
I have 17,000 miles on my 2001 F-250 SD with a 5.4L. Despite what people say about this engine in this big of a truck i think its wonderfull, but lately I have noticed that I am getting a layer of oily dirt coating the Engine. I see no oil in the driveway, and my oil never looks low when i change it but this oil is coming from somewhere. I have never had a vehicle get this oily before so I am curious is this a ford 5.4 trait or do i need to visit a dealer for a leak they probably can't find.

 

Sound like what you would get from a lose valve cover check and see if all the bolts are tight on them.

 

I had the same problem on my 2000 Supcab 5.4 and found that one of the valve cover bolts (which each have a rubber seal) was leaking. The bolt was tight so I loosened it and repositioned the washer seal and retightened it. I have not noticed the oily residue since. It seams that when those bolts leak the air from the fan spreads it all over the engine bay.