Water Pump Mercedes W169 W245 M266 OM640 Heater Valve A2662000820

Mercedes W169 W245 M266 OM640 Water Pump A2662000820 is an original part from the Water Pumps category, designed for the cooling system in Mercedes compact class vehicles. Thanks to its factory design, it ensures stable coolant circulation, supporting the safe operation of the engine and its accessories. This is a solution for users looking for a proven water pump for their Mercedes that meets factory standards.

Specifications and technical data

• SKU: A2662000820
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2662000820
• Substitutable numbers: A2662000820, A 266 200 08 20, A2662000720, A 266 200 07 20, BG
• Location on the vehicle: Rear
• Category: Water Pumps

Purpose and Function of the Pump in the Cooling System

The presented water pump is a component of the cooling system responsible for forced fluid circulation between the engine and the heat exchanger. In Mercedes W169 and W245 series vehicles with M266 and OM640 engines, it maintains a stable operating temperature, which translates to protecting the engine from overheating and ensuring smooth operation across the full load range.

Thanks to a design tailored to the specific drive architecture, the pump works with factory hoses, housings, and mountings, which facilitates installation and reduces the risk of leaks. Precise fit for the Mercedes cooling system allows for maintaining the operating parameters intended by the vehicle manufacturer.

Vehicle Placement and Installation Aspects

The pump is designed for installation at the rear of the powertrain, in accordance with the factory construction layout. This vehicle placement affects the routing of cooling hoses, service access, and the method of driving the pump. When replacing it, pay attention to:

• the condition of seals and mating surfaces,
• the correct routing of coolant hoses,
• bolt tightening torque in accordance with service documentation,
• bleeding the system after installation.

Due to its specific location, it is recommended to carry out the replacement in a workshop environment or with the use of appropriate service tools to maintain sealing and correct installation geometry.

Benefits of Using an Original Mercedes Pump

Using a water pump dedicated to specific Mercedes models allows for maintaining the integrity of the entire cooling system. Key benefits include:

• Compatibility with M266 and OM640 engines – design tailored to the thermal characteristics of these engines.
• Consistency with factory equipment – cooperation with original hoses, housings, and mountings.
• Stable operating parameters – maintaining proper coolant flow under various load conditions.
• Possibility of verification by OEM and interchangeable part numbers – easier identification of compatibility with a specific vehicle configuration.

A cooling system configured in this way promotes even engine operation, reduces the risk of localized overheating, and supports the durability of other components, such as seals, cylinder head, or turbocharger (if present in the specific version).

Product Characteristics and Practical Application

The water pump offered here comes from the Mercedes group and is a part intended for reinstallation in vehicles where maintaining the original cooling system specification is required. Used condition means the part has been previously operated, so a standard workshop inspection is recommended before installation, including an assessment of play, leaks, and impeller operation.

In practice, water pump replacement is recommended, among other things, in case of:

• detected coolant leaks in the pump area,
• excessive bearing noise,
• engine overheating despite a functional thermostat and radiator,
• comprehensive cooling system service after a high mileage.

Selecting the pump based on OEM and interchangeable part numbers minimizes the risk of purchasing an incompatible part and reduces vehicle downtime in the service center.

Technical Support and Educational Materials

When planning service work, it is advisable to use technical materials regarding diagnostics and part selection by OEM number. For fuel supply systems, an article describing the principles of selecting and regenerating fuel supply components may be helpful – a detailed discussion can be found in the material Fuel System – Injectors, Pumps, and Fuel Tank: Maintenance and Regeneration, which organizes the approach to identifying parts by numbers and operating parameters.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other parts from the same group, such as additional pumps, circulation components, or cooling-related components, check the available parts in the Mercedes Water Pumps category.