BMW F90 M5 F91 F92 M8 Radiator Expansion Tank Bottle 8090271

The BMW F90 M5 F91 F92 M8 Radiator Expansion Tank Bottle is an original component designed to operate under demanding high-temperature and high-pressure conditions. As part of the Expansion tanks group, it ensures stable operation of the cooling system, proper coolant volume compensation, and safe pressure relief in high-performance engines.

Specifications and technical data

• SKU: 8090271
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8090271
• Substitutable numbers: 8090271, 17138090271, KD
• Category: Expansion & Overflow Tanks

Purpose and function in the cooling system

The presented expansion tank is a cooling system component designed specifically for the high-performance BMW F90 M5 and F91/F92 M8 models. It is responsible for maintaining a coolant reserve, compensating for volume changes during heating, and stabilizing pressure throughout the circuit. A properly selected tank minimizes the risk of engine overheating, airlocks in the system, and uncontrolled leaks.

Construction and fitment for BMW F90 M5 / F91 F92 M8

The original design of the tank is optimized for the engine bay geometry of M versions, which facilitates installation at factory mounting points and ensures proper routing of cooling hoses. The shape and placement of the connectors are adapted to the stock hose system, allowing the component to work with the factory water pump, radiator, and other components without the need for modifications.

As an OEM part, the tank maintains compliance with factory cooling system operating parameters, which is particularly important in engines with high power output and high thermal load. The correct working capacity and properly designed internal chamber promote stable coolant circulation and correct venting.

Benefits of using an original expansion tank

Using an original expansion tank in a BMW F90 M5 or F91/F92 M8 allows you to maintain the consistency of the entire cooling system with the manufacturer's specifications. This solution is particularly recommended when:

• replacing a damaged or leaking tank,
• servicing the cooling system after engine overheating,
• restoring the vehicle to full efficiency after a collision or body and mechanical repairs.

A well-chosen tank reduces the risk of pressure drops, coolant loss, and improper operation of temperature and fluid level sensors, which translates into more stable operating conditions for the engine.

Product condition and service application

The offered item is used, making it an attractive cost-effective alternative to a new part while maintaining the original manufacturer's specifications. This type of component is suitable for both routine repairs and comprehensive cooling system service, where maintaining factory geometry and compatibility with other sub-assemblies is crucial.

Expanding BMW cooling system service

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other elements from the same group, such as additional tanks, mounting elements, or covers, check out the available parts in the BMW Expansion tanks category.

For users interested in a broader approach to vehicle service, including lighting, a practical guide on selecting and replacing used headlights and accessories may be useful – you can find it in the article See more and better – a complete guide to selecting and replacing used LED and Xenon headlights, which helps you consciously plan service work on your BMW using original components.