Genuine Mercedes 278200120180, A278200120180 Water Pump; Factory Rebuilt – Mercedes | 2782000501 278200050180 2782001201

The engine water pump on your Mercedes circulates a mixture of water and engine coolant throughout the engine to maintain an optimal operating temperature. When the engine exceeds its optimal operating temperature, the engine water pump pumps the water and coolant mixture into the radiator to bring down the engine temperature.

If the engine water pump fails on your Mercedes, the water and coolant mixture will not be able to circulate through the engine to maintain optimal temperature. In some cases, the pump can leak allowing the water and coolant mixture to drip or pour from the engine causing the engine to quickly overheat. On newer vehicles with electric engine water pumps, a failed pump can cause the vehicle to enter limp home mode, only allowing the vehicle to reach a maximum speed of 25 MPH to prevent the engine from overheating.

Signs of a Faulty Water Pump

• Coolant leaking under your Mercedes
• Engine overheating
• Whining or grinding noises from your engine
• Check engine light on with a water pump fault

Belt run water pumps may also cause other accessories to stop working when the pump fails as it can cause the belts to jump off the pulleys.

Replacing Your Mercedes Water Pump
Generally water pumps are only replaced when they fail. However, due to how difficult it is to access some water pumps, to prevent failure it is recommended to replace timing belt driven water pumps during the replacement of the timing belt and timing chain.

Replacing your Mercedes water pump can be very extensive depending on where it is mounted on the engine. Due to this, it is recommended to replace any connecting hoses, the thermostat, timing belt and tensioner if applicable, timing chain with guides and tensioner if applicable, as well as any other seals or hoses that need to be removed to access the water pump.

Mercedes Water Pumps.