Originally Posted by Lepke
If the engine was in below freezing temperatures with unprotected coolant in the head or block, it could easily have a crack. If the engine was fine before storage and the problem showed up on the first start, then it's probably not the head gasket, but a cracked head or block.
I have had engines freeze, what has happened is, usually the core plugs pop out.
Sometimes they just move a little further out, sometimes they pop out.
But they dont always pop out. My 1995 SL2 last winter froze solid, could not crank it, temperature in the teens at night. It took a week for the deep freeze to pass. I feared the worst, but engine was fine. The coolant level before the freeze up was low, I kept getting low coolant light and had never filled it up. And the antifreeze was too weak to prevent a freeze up of the block. everything survived, I was blessed, there was room for the ice to expand inside the motor.