Can a bad head gasket cause white smoke to come out of the exhaust?

Heavy white smoke is usually caused when the engine burns Transmission Fluid, such as when the modulator valve is defective, causing transmission fluid to be sucked into the intake system.

A stuck closed thermostat could cause the engine to overheat. If the engine overheated badly and repeatedly, a cylinder head could crack and allow coolant to enter the combustion camber. This condition would cause white smoke to blow out the exhaust.