So, I just noticed I had this yellowish gunk starting to build up inside my oil filler neck. What the hell is it? It couldn't be coolant could it? Doesn't coolant make the oil milky instead of chunky?
ur screwed. thats coolant in the oil. i had the same problem when i blew a head gasket. def. take care of that before you wash your main bearings out. It happened to me. same Fing thing.
Thats what water/coolant vapor mixed with older oil looks like.
Either you have some coolant in the oil or its sat for a long time and moisture collected in there. As it evaporates and rises to the highest point in the motor (underside of valve cover/filler neck), it mixes with oil vapor to produce...that.
Check oil color and coolant level. Run some seafoam through the motor just in case.