Start plugging the holes (CCV, VCGs, oil cap, etc.) and it has to go somewhere - it'll find the weakest spot. Appears yours was the stem seals. From what you describe, it sounds like it. Does it clear up after you run it for a few minutes and keep it running? I suspect it's not good for the cats either, so it should be addressed. Like I said, mine isn't bad yet, so I'll go in in a few weeks. I'm hitting Watkins for a week with my other car (looks like it's going to piss rain 2 of the 4 days
), then off to San Antonio for a week or two (work).
I'll share whatever I find out - additives, costs, recommendations, etc.
Cheers.