I was thinking I should flush the coolant in the 240 and so it was warm through the day yesterday so I did it. I took the thermostat out and cycled the coolant through the block without the thermostat.
When I went to fill it I put the thermostat back before I added the coolant so there was water in the block. I put pure antifreeze in the radiator and ran it till it drew down the coolant into the engine. Then I added the premix 50/50.
I put almost a gallon of pure antifreeze in and then the premix.
The temps were well below freezing last night.
I drove it this morning and and all the coolant leaked out from the front of the engine. I couldn't see any broken hoses. Is there any scenario that one could imagine where this is less than catastrophic.
I really like this car but if the engine block is cracked I am up the creek. I tried to start the 300D but it wouldn't start. I am really feeling down now.