Hey Jim,
I re-read your original statement...'plenty of oil and the radiator was FULL'.
Your last entry says 'missing TWO gallons of water' .
Trying to diagnose that and wondering...seriously how that could be
Anyway, I'd suspect a HEAD gasket for sure, as your evidence of 'metalic' smell AND white smoke is direct indicators of blown gasket. Low water leads to high heat leads to max metal expansion leads to clatter and weak point (gasket) failure. Good luck and let us know,eh
