BMW issued a recall on the 3 SERIES model

On certain 318I, 325I and M3 vehicles, elevated pressure in the cooling system due to overheating could result in cracking of the heater core end piece. Should this happen, coolant could be expelled onto the lower right leg of the driver, possibly resulting in personal injury and/or fogging of the interior surfaces of the windows causing reduced driver vision. Correction: A thermistatic bypass valve will be installed to control coolant temperature in the heater core. Also, a new design radiator cap will be installed to control pressure and provide greater overflow.