So my wife has a 93 325i which only has 132,000kms on it and is in real good shape. The problem were having is occasionally after driving it for a while itll overlfow coolent everywhere on the floor when turned off, from the overflow cap... I just replaced the waterpump and tried to do the thermostat but there wasnt one in the car, and i ended up getting the wrong one so currently it doesnt have one, but i am so confused on what the problem is. if i blow in the overflow and plug the little bleeder the coolent goes no where yet if i feel the radiator hoses both top and bottom, they seem to have no coolent just air in them. And only air comes out the bleeder when i squeeze them. Its like the resovior stops circulating and overflows as i drive (cause i smell coolent as i drive from time to time) and then fills up with air, and the coolent in the resovior heats up cause its not circulating and then has to go somewhere and overflows... if anyone can help that would be much appreciated. Oh and it never rised past half way on the temperature.