While I was doing some routine mantinence I found some oil in the air box. The filter looked fine as there was no oil on the filter itself but the bottom of the air box has oil in it. I bought a PCV valve thinking that this is the cause of the problem but I can't find where the PCV valve is located. I talked to another parts store and they said it was in the valve cover & that it doesn't have a normal looking PCV valve. The one a got is a MotorCraft PCV that's brown in color and straight and has a little check inside that rattles around. My question is where is the PCV valve and is the oil in the air box something to worry about?

 

The PCV valve is a baffle made into the valve cover on the 5.4 3 valve. I have seen on some engine especially the 4.0 SOHC if you fill the engine oil fast without pulling up the dipstick to vent oil will get in the air cleaner assembly. Not sure if that is the case with the 5.4 but it could be as simple as that and not blowby.