ya,white sweet smelling smoke is a leaking HG, thats what mine was doing.
also when it was warmed up i had high pressure in the system and it blew the old rad,then an old hose and finally fully went..
rite befor they went i was getting bubbles into my overflow tank and 5 min of driving later i looked behind me and had a huge plume of white smoke and the temp gauge began to climb. but i never let it get even half way up. i limped her home as eas as i could and its been down about 2 months now. but when fixed should be pretty quick..