well my car is a 1980 300SD i replaced the radiator a few days ago and it was still overheating then a few days later it stopped overheating and I noticed a hole in the top of the radiator where steam was coming out so it seems now if i keep filling it up it wont overheat but its loosing alot of warer in steam. The thermostat is in the right way because i took the old one out and made sure i put the new one in in same direction. I am realy confused... My old radiator is leaking also thats why i took it out so im gonna get that patched on tuesday, replace it and see if that helps any