Car shut down while driving and won't start

Hello... I bought a new car yesterday, 99 Volvo C70. I bought it knowing that the radiator would need replacement, as it is leaking.On the drive back, home the engine stalled. After I stopped and tried to turn it back on, it wouldn't start.About 5 minutes before that, I felt as if the engine was slightly losing power. On the way I stopped twice to add water into the cooling system since it's leaking.When I opened the bonnet the engine was smoking a bit, at first I thought it had overheated, but I remember for sure that the dial was showing that the engine temperature was normal when it stopped. (If it was overheating I would have stopped immediately).I called a tow truck and they brought the car home. At home, I tried to start the car again. The engine is cranking, but won't start. I accidentally left it in first gear when turning the key and it moved slightly forward, so the engine must be turning over too...I checked around the head gasket and there is no obvious leak there. The coolant is dripping from the radiator, same like it was when it was running, and when I try to start the car, it starts to push out the coolant more, as well as push it out of the coolant reservoir when I leave the cap off.Does anyone have an idea what it could be? Obviously I will take it to a mechanic but I won't have time until next week, I work until then.Any help massively aprreciated. via /r/cars http://ift.tt/2rR2WWv