I have a 03 4.7 with 85k and have changed it over to amsoil over a year ago it runs great but i have noticed this yellow gunk on the oil fill insert and in the tube. Does anyone know what that could be?

 

i think its condensation. it tends to build up more in motors that drive short distances than those that make longer drives. wipe it out as best you can, but it really doesn't hurt anything. check your pcv valve and make sure it rattles.

 

Well that makes sense its driven about 6min round trip to work 3 there and three back so i guess that could be it. I know what the pcv valve is and its usually on the valve cover but im not sure thats where it is on the 4.7.

 

x2 on the condensation. I only drive one minute to work (literally) so I get a lot of it built up in my crankcase cap every time I change the oil.

 

yep, used to have the same problem, now its a 30 minute drive minimum everywhere lol

 

Yep, take it for a nice long drive (at least an hour) once a month to get the oil good and hot and to evaporate any moisture in the crankcase.