So the mysterious dissappearing coolant from my son's 340 has finally showed up in the oil. He rebuilt it for his senior project a couple years ago. He didn't get a lot of supervision and I think something was assembled wrong. The car hasn't been driven much the last year. The coolant was dissapering and wasn't leaking externally that we could see. The water in the oil showed up about a month ago when I was giving it it's monthly start up. I'm thinking head gasket. Could it be anything else? Can I diagnose it without pulling the top end apart? Thanks for any replies.
