Lot's of good info so far, and could be several things mentioned, but the quote above bugs me more then anything else? 3/4 of a inch isn't much down that passage? I was on the "Head Gasket" bandwagon when I first read this, but even that issue should be deeper then that if I recall?
I'll keep thinking on it and let you know if a "eureka" moment comes to me. :)
