I have a 95 mazda 626. I recently replaced my thermostat, water pump, and hoses, and randomly the other day alot of steam started coming out of my engine. When I looked under the hood a stream of steam was coming from the middle of the engine, also there was a large pool of coolant in the middle of my engine. My guess is that one of my freeze plugs is bad. But im not sure, I cant see where it's coming from. The oil looks fine so the coolant isn't mixing with it (thank God), and it didnt overheat at all. Its just steaming. I havent driven it since because I dont want to cause anymore problems. I've read that replacing the hard to get to freeze plugs can be very expensive. What should I do?