How is the oil filler held into the valve cover on the 6.0? It seems a little loose and I think it may be leaking at the base a bit. The valve cover has a black coating of oil/dirt on it. Is there a gasket or O-ring that seals it?
Yes there is an o-ring at the base where it goes into the valvecover. Cant remember if it's avail separetly, see the dealer, or go to auto parts store and buy a cheap cap and rob the o-ring off it to replace on to your original tube.
Twist it out/off just like you would the oil fill cap. Would probably help if you took the black plastic valve cover shield off. Grab a can of carb cleaner at the store too so you can spray off all the oil goop and residue. If you have never had the covers off I believe it is an 8mm. Top center of the upper cover is 1 bolt. Remove the upper intake cover first to reveal the other bolts to get the rh cover off.