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 range, designed for the S55 power unit in BMW M-series sports models. This used, factory-spec pump ensures proper coolant circulation, which translates into stable engine operating temperatures and safe utilization of its full potential.

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, and heat exchangers. For the high-revving BMW M3 F80 and M4 F82 units, maintaining a stable operating temperature is crucial for component durability, precise engine management, and repeatable performance.

The original pump from the BMW family has been designed for the specific thermal loads of the S55 unit, ensuring:

• properly calibrated coolant flow efficiency,
• compatibility with factory engine management and auxiliary equipment,
• consistency with the factory cooling system operating characteristics.

Benefits of using an original BMW pump

Using an original water pump in a BMW M3 F80 / M4 F82 allows you to maintain factory engine performance parameters, which is particularly important in vehicles with increased power and a sporty character. Precise fitment for the S55 unit reduces the risk of leaks, incorrect accessory belt tension, or cooling system errors.

Compared to aftermarket replacements, this OEM component provides:

• compliance with factory assembly tolerances,
• predictable behavior across a wide range of thermal loads,
• easier diagnostics during future service inspections.

Condition, fitment, and installation

The offered water pump is a used component, which in the case of BMW M parts often allows for combining high manufacturing quality with an attractive purchase price. Before installation, it is recommended to perform standard checks for leaks, play, and the condition of connections, in accordance with BMW service procedures.

For proper part selection, it is worth using the manufacturer's markings and interchangeable part numbers, as well as comparing the body geometry, port layout, and mounting method with the currently installed component. This approach minimizes the risk of mismatch and reduces workshop time.

Technical support and selection by part numbers

In case of any doubts regarding the compatibility of the pump with a specific BMW M3 F80 or M4 F82 configuration, verifying by manufacturer part numbers and vehicle data is a good solution. This helps avoid installation issues and ensures compliance with the factory cooling system specifications.

If you would like to deepen your knowledge on the diagnostics and selection of pump components and other supply system parts, the article describing the principles of operation and maintenance of fuel supply systems may be helpful: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration. Although it concerns a different system, it presents a useful approach to identifying parts by OEM numbers and their operation.

Expansion and modernization of BMW M

Owners of BMW M3 F80 and M4 F82 models often combine water pump replacement with other drivetrain and cooling system modifications. In such cases, it is worth paying attention to the differences between standard components and those from the M and M Performance lines, which are designed for higher loads and more dynamic driving. More information on this topic can be found in the material: BMW M Performance: how do BMW M components differ from standard ones?.

Related items from the BMW Water Pumps category

If you are planning a comprehensive repair or modernization of the engine area in your BMW and need other elements from the same group, such as pump housings, impellers, or connection casings, check out the available parts in the BMW Water Pumps category.