BMW 3 Series E90 E91 E92 M57N2 Radiator Bottom Thermostat Coolant Hose 7794748

BMW 3 Series E90 E91 E92 M57N2 Radiator Bottom Thermostat Coolant Hose is an original cooling system component designed for M57N2 diesel units in the E90 series. Thanks to its factory geometry and precisely selected diameter, it ensures stable coolant flow and proper cooperation with other system components. It is a practical solution for users looking for a proven coolant hose tailored to the specifics of the BMW engine.

Specifications and technical data

• SKU: 7794748
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7794748
• Substitutable numbers: 17127794748, 7794748, 17127789589, 7789589
• Category: Hoses, Lines & Pipes

Purpose and function in the cooling system

The coolant hose used in the M57N2 engine is responsible for transporting coolant between key system components, which helps maintain a stable operating temperature for the power unit. A properly shaped pipe minimizes the risk of kinks, local constrictions, and uncontrolled stresses that could lead to leaks or a decrease in cooling efficiency.

In the case of BMW diesel engines, it is particularly important to maintain proper fluid flow, as these units generate high thermal loads. Using a dedicated coolant hose helps reduce the risk of overheating, uneven temperature distribution, and accelerated wear of cooperating components.

Construction and fitment for BMW E90 M57N2

The hose in question belongs to the Hoses, pipes and tubes category, designed for precise fluid routing in the engine bay. Its shape and length have been selected to ensure:

• secure seating on cooling system connectors,
• adequate clearance relative to adjacent components,
• stable operation under changes in temperature and engine load.

Thanks to a design consistent with BMW's factory specifications, the hose works with original clamps and mounts, which facilitates installation and subsequent maintenance. Such a fit reduces the risk of incorrect hose positioning, which could result in rubbing against other elements or excessive material stress.

Benefits of using an original BMW hose

Using a coolant hose dedicated to the E90 with an M57N2 engine provides a number of practical operational benefits:

• Cooling system compatibility – the hose was designed for a specific engine and body configuration, which translates into a proper fit.
• Stable flow parameters – the correct inner diameter and geometry are maintained, which supports even coolant circulation.
• Easier diagnostics and service – using components consistent with factory documentation makes work easier for mechanics and speeds up potential repairs.
• Consistency with other components – the hose works in harmony with other cooling system elements, which helps maintain predictable behavior of the entire system.

Product characteristics and practical application

The item is classified as a used BMW part, making it an attractive solution for users looking for a reasonable compromise between cost and functionality. In the case of cooling systems, it is essential that the hose maintains tightness, proper working flexibility, and correct geometry – these features are crucial when selecting a replacement for the M57N2 engine.

This type of coolant hose will prove useful both for standard replacement of a worn-out part and during broader service work related to the cooling system, such as replacing the radiator, thermostat, or water pump. Maintaining compliance with the factory BMW design helps keep the power unit's operating parameters predictable and reduces the risk of unplanned vehicle downtime.

Additional information and related items

If you are planning a comprehensive repair or upgrade of the cooling system area in your BMW and need other items from the same group, such as flexible water hoses, rigid guide pipes, or additional return lines, check out the available parts in the BMW Hoses, pipes and tubes category.

When selecting used cooling system components, it is worth paying attention to their visual condition, storage method, and compatibility with a specific engine version. To better prepare for your purchase and avoid common problems related to vehicle tuning or upgrades, you can use the practical tips described in the article Buying used car parts – the most common mistakes when choosing parts for tuning.