Engine blocks can crack from many different reasons. Improper antifreeze ratio during freezing temperatures, internal engine component malfunctions (such as throwing a rod), etc.
A faulty gasket, overheating of the engine or old age. Or, a combination of any of these causes.
The cause of white puffing smoke in a diesel is the crack pipe ventilator seal. Fix that it keeps the crack inside.
Antifreeze in the oil of any engine means there is a crack in the head gasket, or worse, in the block.
Lack of anti-freeze in sub-freezing temperatures. The water in the block freezes and expands.
Insufficient protection against freezing in cold weather or severe overheating.
Are you talking about a crack in the engine block? Sorry, it's not repairable.
Crack.
Moisture
White smoke is usually vaporized coolant. You may have a blown gasket or a crack somewhere.
Crack.
crack
if there is oil in the coolant system it could be a crack in the intake, a ruined intake gasket, a cracked cylinder head