BMW 1 3 Series E87 E90 E91 Diesel M47N2 Cooling Radiator Water Hose Pipe 7790437

BMW 1 3 Series E87 E90 E91 Diesel M47N2 Cooling Radiator Water Hose Pipe is an original cooling system component from the Hoses, pipes and lines category, designed for BMW diesel engines from the M47N2 family. This used OEM part ensures factory-spec coolant flow geometry, which promotes stable engine operation and reduces the risk of overheating during daily use.

Specifications and technical data

• SKU: 7790437
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 11537790437
• Substitutable numbers: 11537790437, 7790437, 11537795761, 7795761, 11537805358, 7805358
• Fuel type: Diesel
• Category: Hoses, Lines & Pipes

Purpose and function in the cooling system

The presented water hose is a component of the cooling system in BMW 1 Series E87 and 3 Series E90/E91 models with the M47N2 diesel engine. It is responsible for the controlled transport of coolant between key engine components, which allows for maintaining optimal engine operating temperature under various load conditions.

By maintaining the original diameter and cross-sectional shape, the hose supports proper fluid circulation, minimizing local pressure drops and limiting the risk of air bubbles forming in the system. This is particularly important in modern diesel units, where stable cooling affects the durability of the cylinder head, seals, and auxiliary equipment.

Advantages of using an original BMW hose

Using an original water hose in the M47N2 diesel engine brings a number of practical service and operational benefits:

• Factory fit – the hose is designed for specific BMW models, which facilitates installation and eliminates the need for modifications.
• Stable cooling system operation – the correct shape and length of the hose promote even coolant flow.
• Compatibility with diesel equipment – the hose design takes into account the thermal specifics of diesel units.
• Possibility of using interchangeable part numbers – facilitates the selection of the appropriate component for different equipment versions.

A used OEM element is a reasonable choice for repairing BMW cars with diesel engines, allowing for the preservation of factory cooling system performance at controlled service costs.

Part condition and installation aspects

The offered water hose is a used part, which in practice means it comes from disassembly and is intended for re-installation after verifying compatibility with the given vehicle. Before installation, a standard cooling system check is recommended, including connection tightness, the condition of clamps, and the level and quality of the coolant.

Replacing the water hose in the M47N2 engine is a typical service operation, performed, among others, in the event of:

• detected coolant leaks,
• visible cracks or deformations of the old hose,
• preventive cooling system maintenance in high-mileage vehicles.

Selecting the right element is facilitated by the presence of the OEM part number and interchangeable numbers in the technical specification, which allows for precise matching of the hose to a specific BMW configuration.

BMW hoses, pipes and lines – system expansion and modernization

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 return lines, supply hoses, or additional cooling system pipes, check out the available parts in the BMW hoses, pipes and lines category.

Why choose used original parts for BMW?

In the face of rising costs of new components and periodic availability issues, used OEM elements – such as this water hose for a diesel engine – are becoming an increasingly popular solution for servicing premium cars. The original geometry and material of the hose ensure better compliance with the manufacturer's design than many aftermarket replacements, which translates into predictable cooling system behavior.

If you want to learn more about the arguments for using used original parts in premium brand cars, check out the article Crisis in the new parts market? Why used originals for premium cars (BMW, Mercedes, Porsche) are the hottest trend in 2026, which discusses current service and economic trends.