Starting hard with white smoke

White smoke is a sign of burning engine coolant. To verify that, your mechanic can perform a chemical test at the radiator. That involves drawing air from the radiator, while the engine is running, through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present, the liquid will turn bright yellow.

Also, check to make sure there is no coolant mixing with the motor oil. If it is, the oil will have a creamy tan color to it. One other simple test is this. When the engine is cold, remove the radiator cap and start the engine to see if any coolant comes out. If the system is pressurized by a head gasket, it will blow coolant out of the radiator.