If you had white smoke it is extremely likely that your coolant seals went out. If this is the case, leaving it like that allowed the coolant to pool inside the housings and has corroded the inside of the engine. Unfortunately that would likely mean sourcing a new engine. You can try pouring ATF or other oils in there, but I doubt it's going to do much good. Certainly not likely to hurt though.
edit: dang he beat me to it.
