If an engine is running rich, it is receiving and burning too much fuel and that will yield black smoke. If an engine is somehow burning oil, that will yield white smoke.
Black smoke indicates a rich fuel mixture.
the engine is running
You can drive a diesel engine, or any other type, blowing any colour smoke you wish. Though it is pretty foolish to smoke
Moisture in the exhaust, or a cold running engine.
This engine could have burnt rings in it. There also could be an old leak which is running down on the manifold which would cause the engine to smoke.
could have bad o rings
sounds like you have head gasket problem if the exhaust smoke is white in colour then its engine coolant if its blue smoke then its burning oil you will need to get the engine pressure tested at a garage.
White smoke = Coolant leak, head gasket is the likely culprit. Blue smoke = Engine burning oil. Black smoke = Engine running too rich, wasting fuel.
its probably burning oil, if the smoke is white. if the smoke is black, it means its running rich. if the smoke is white, you have serious internal engine problems
If it stops after a minute or two, it was condensation. If it continues the whole time the engine is running, it's smoke.
Assuming this is a gasoline engine, it is running rich from excess gasoline.
White smoke is antifreeze, intake or headgasket.