Is your oil pan completely full of oil? Nope. There is air in there. And what does air do when it goes from extreme to extreme? It will create condesation, same goes for your rocker boxes. The oil pump system is sealed as it needs to build up pressure but when the oil leaves the pump system and just gets flung around moving parts in the heads and such or returns to the oil pan... BAM there it is... AIR
Damn how did that get there!!
