Blew the head gasket. Badly. Might've warped the head too.
Overheated (badly) on Thursday night coming home from IKEA. Crack in one of the plastic radiator tanks, plus one hose junction blew apart -- redid the lines & installed new radiator (with better mounting & hose routing) Friday and Saturday, filled the cooling system. Couldn't get it to start, smelled combustion gasses in the coolant reservoir. Pulled the #2 spark plug and coolant game gushing out of the hole. Almost as much coolant in #3, a bit in #1 & #4. Blew it out as best I could, sprayed some oil down the cylinders to prevent rust, called it a night.
It had overheated once earlier this month when the thermostat failed in the closed position. Replaced the t-stat and refilled the cooling system and everything seemed fine except I kept having to "burp" air out of the system. I'm thinking (now) that the gasket started to go at that point and what I was burping was combustion gas. Plus the temp gauge was getting to 230*F then drop to 150*F when the t-stat opened .. I suspect the higher pressures (from the higher temperatures) were an added bit of stress that the hose junction couldn't handle. Crack in the radiator tank was a stress fracture from the mounting arrangement...
On the plus side, the head gasket is cheap, the head bolts are cheap. It'll give me an excuse to install the adjustable cam sprocket I picked up awhile ago, maybe re-work the exhaust with a better-flowing manifold if I'm feeling ambitious. Gotta get something else going for a daily-driver while the Bus is down though.
