[funster]

It definitely sounds like a coolant leak issue to me. The smoke you saw was likely steam. It could just be a broken hose. It would be important to make sure that you have the right proportion of antifreeze to water in your system. Since you dumped a gallon of water in you should dump a gallon of antifreeze in as well, and make sure it's the right kind of antifreezee for your porsche. The last thing you want is for your engine block to crack due to freezing. Good luck with finding a mechanic.