Engine Water Pump BMW F80 M3 F82 M4 S55 Coolant Water Unit 7846361

Engine Water Pump BMW F80 M3 F82 M4 S55 Coolant Water Unit is an original cooling system component from the Water pumps group, designed for the S55 power unit in BMW M-series sports models. This used OEM part ensures a factory fit, maintaining proper coolant flow parameters and stable engine operation across a wide range of loads.

Specifications and technical data

• SKU: 7846361
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7846361
• Substitutable numbers: 7846361, 11517846361
• Category: Water Pumps

Purpose and function in the cooling system

The water pump in the S55 engine is responsible for the forced circulation of coolant between the engine block, cylinder head, radiator, and other system components. In high-performance turbocharged units, such as the S55 in the BMW F80 M3 and F82 M4, the proper operation of the pump is crucial for maintaining a stable operating temperature, protecting against overheating, and preserving full engine performance during dynamic track and road driving.

Thanks to its factory OEM design, the pump works in harmony with the original engine management system, maintaining correct flow and pressure characteristics. A properly selected impeller, housing, and seals minimize the risk of cavitation, leaks, and performance drops during long-term operation.

Advantages of using an original BMW pump

Using an original water pump in the S55 engine allows for maintaining the consistency of the entire cooling system with the manufacturer's factory specifications. This is particularly important in high-power vehicles, where every element of the thermal system operates under increased loads. By choosing this pump, you gain:

• factory fit for cooling system mounts and hoses,
• proper cooperation with original sensors and engine management,
• maintenance of the cooling characteristics intended by the manufacturer across the full RPM range,
• reduced risk of overheating issues during intensive use.

For BMW M3 F80 and M4 F82 users who expect predictable vehicle behavior on the track and in daily driving, choosing an original BMW water pump is a technically safe solution that is consistent with the vehicle's design assumptions.

Condition, verification, and selection based on technical data

The offered pump comes from disassembly and is a used component, which allows for an economical repair of the cooling system while maintaining the original specification. Before installation, it is recommended to perform a standard check of tightness, play, and the condition of the connectors and sealing surfaces to ensure trouble-free operation after installation.

Selecting a pump for a specific BMW F80 M3 or F82 M4 should be based on the vehicle's identification data and part catalog numbers. This minimizes the risk of structural incompatibility and ensures full compatibility with the existing cooling system.

Integration with other powertrain components

A functional water pump has a direct impact on the durability of the S55 unit, turbochargers, and engine accessories. A stable operating temperature limits thermal stress, reduces the risk of cylinder head and head gasket deformation, and supports the uniform operation of the lubrication system. In sports vehicles, where sudden load changes are frequent, a properly functioning water pump is one of the key elements in maintaining the reliability of the entire drivetrain.

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as housings, connectors, or additional cooling modules, check the available parts in the BMW Water pumps category.

Technical support and knowledge about fluid systems

When replacing the water pump, it is worth paying attention to the quality of operating fluids and the correct system bleeding process. For users who want to expand their knowledge on the selection and operation of components from the pump group and diagnostic methods, the following article will be helpful: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration. Although it concerns a different working medium, it discusses universal issues related to pump operation, their selection by catalog numbers, and the principles of proper operation.