Sadly that is a sympton of a bad head gasket or cracked head. The engine compression is by passing a gasket and forcing the water out of the coolant jug.
The North Star engine damages easily if overheated. At 260 + degrees the engine is already damaged. Both heads need to come off, and checked. Hope fully the block assemby is OK. When you mix aluminum and heat in an engine any variance in temperature causes engine damage.
You can purchase a CO2 kit at any parts store that allows you to test is CO2 is in the coolant system. I think it would be a waste of money because the top of the engine is already ruined. It probably was bad before you got the car and the owners knew it. Hence the sale of a nice car.
You may want to consider a low mileage salvage engine.
Good Luck
Friday, May 26th, 2006 AT 7:26 AM