[Woodyboat]

I am not a pro-mechanic by any means. But I do know that milky oil is a sign of moisture that has gotten mixed in. And so, I think you're correct because a bad head gasket is really the only place where moisture could get in.

Has your coolant level changed?

Also, does the oil have any sort of coolant odor?

If not coolant odor, what about any hint of gasoline odor. I think that, if gas has gotten in there, that may give a similar symptom.

I'm surprised that others, who are more knowledgeable than me, have not chimed in.