BMW 3 5 Series E90 E91 LCI F10 F11 N57 Connector Coolant Hose Flange 7803751

BMW 3 5 Series E90 E91 LCI F10 F11 N57 Connector Coolant Hose Flange is an original cooling system component designed for selected BMW models with the N57 engine. Thanks to its factory geometry and precisely selected diameter, it ensures stable coolant flow and proper cooperation with the radiator and other system components. This is a solution for users looking for a proven, factory-standard coolant hose for their BMW 3 Series E90/E91 LCI and 5 Series F10/F11.

Specifications and technical data

• SKU: 7803751
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7803751
• Substitutable numbers: 7803751, 11117803751, EM
• Category: Other Engine Parts

Purpose and compatibility with BMW models

The presented coolant hose has been designed for BMW 3 Series E90/E91 LCI (facelift) and 5 Series F10/F11 vehicles equipped with the N57 engine unit. This means that its shape, length, and connection diameters are adapted to the factory routing of lines in the engine bay, which facilitates installation and reduces the risk of stress or leaks.

By maintaining the original design specifications, the hose works with the factory radiator, flanges, and clamps intended for this system. This allows for maintaining the proper flow of coolant, which is crucial for maintaining the appropriate operating temperature of the N57 engine under daily operating conditions and during high-load driving.

Technical and functional characteristics

The coolant hose in this application serves as a conduit for transporting coolant between the radiator and other system elements. The design of the hose is adapted to operate at elevated temperatures and under the pressure generated by the coolant pump. The properly selected material flexibility reduces the transmission of vibrations from the engine to the radiator while ensuring stable shape retention during operation.

In practice, a correctly selected coolant hose helps to:

• maintain the tightness of the cooling system within typical operating temperature ranges,
• ensure uniform coolant flow through the radiator,
• minimize the risk of engine overheating resulting from restricted flow or leaks,
• maintain factory hose routing in the engine bay, which facilitates service and diagnostics.

Application in cooling system service and repairs

Replacing the coolant hose is recommended in situations where signs of material aging, cracks, splits at the flanges, or coolant leaks appear on the surface of the hose. In the case of N57 units, which often operate under higher loads, the condition of the hoses has a direct impact on the thermal safety of the engine. Using a component that complies with factory specifications allows for reducing the risk of failures resulting from improper fitment of aftermarket replacements.

During installation, it is worth paying attention to:

• the correct positioning of the hose relative to other elements in the engine bay,
• the condition of the clamps and flanges to which the hose is attached,
• proper bleeding of the cooling system after completing service work.

Product condition and benefits of choosing an original part

The offered coolant hose is an item from the used BMW parts category, which allows for the economical restoration of the cooling system's efficiency while maintaining factory geometry and fitment. In practice, this means the possibility of using a part originating from original BMW production, without the need to resort to unreliable replacements with different material characteristics.

For the user, this means:

• better fitment to the existing cooling installation,
• preservation of factory hose routing and mounting points,
• consistency with other system elements in a given BMW model.

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 cooling hoses, flanges, or expansion tanks, check out the available parts in the Other BMW category.

Technical support and part selection

When working with advanced power units and extensive cooling and fuel systems, it is worth using reliable sources of knowledge. If you are interested in comparing technical solutions used in sports versions versus standard models, including differences in engine, cooling system, and brake construction, take a look at the article Audi RS vs other models – what is hidden under the hood and chassis?, which discusses these issues using the Audi range as an example and allows for a better understanding of manufacturers' approaches to designing key components.