When I opened my oil filler neck I noticed this white scum foamy stuff lining the neck. I changed my oil a few days back when I first noticed this. The oil I drained out looked fine, wasn't white or foamy at all. Has anyone else expereinced this? I'm hoping that it's just something that happens as oil gets splashed up into the filler neck and not caused by antifreeze in the oil. Any thoughts? (Also, I didn't notice anything odd about oil I drained, like I didn't see any water or antifreeze in it.)