Coolant Radiator Reservoir Tank for BMW 328d 2014-2018 2.0L 17137642160 Coolant Overflow Expansion Bottle with Cap and Sensor for BMW M2 435i 335i. Part Number:, With Cap and Sensor. Installation Instruction: Turn off and cool down the car, remove the bolts and the reservoir, allow the remaining coolant to flow back into the drain pan, replace the new reservoir tank and reinstall the coolant hose to the radiator and tighten the clamp, finally check if function well.