Normaly by the frost plugs seizing and the engine splitting the cylinder walls during thermal expansion of ice in the cooling jackets
Yes
Are you talking about a crack in the engine block? Sorry, it's not repairable.
yes
It should not
no
If ice forms anywhere in the engine, it can crack the block.
crack the engine block and oil mixes with water or antifreeze.
Most definitely.
Lack of anti-freeze in sub-freezing temperatures. The water in the block freezes and expands.
Antifreeze helps by not allowing the coolant to freeze and possibly crack the water passages of the block.
The repair is most likely more money than the car is worth, you need a new engine block.
Yes.If you have no antifreeze in the radiator or engine,sometimes it will freeze.Usually a freeze plug in the engine will pop out before any major damage is done. Sometimes the block will crack,or the radiator will crack or burst if no anti freeze is in the system.