I recently bought this car so I dont have a lot of history to tell. The car started heating up while I was driving on the freeway. The temperature reached its maximum, so I pulled over. I opened the hood and saw a lot of water coming out of the water reserve tank. I waited a few minutes for the car to cool down and then I putted some more water in. The cooled down and I drove it home (abt10 mi) and made it with no more problems. What could be the cauee of this heat? Should I replace the thermostat? Please help. Thank you.