IIRC, blue smoke means you are burning oil. Eg. piston rings / valve stem seals etc.
Black smoke is over fueling (common with diesels)
White is burning water (steam)
From what I gather, you are burning water, and your over flow has beeen filled....
Im my opinion, somewhere along the line the engine is pressurising your cooling system, whilst on non combustion strokes, the water is leaking back into your engine = head gasket.
The same thing sometimes happen when you break a waterseal in a 13b (rotary).