BMW 1 Series 1 E81 E87 Petrol N45 N46 Cooling Radiator Water Hose Pipe 7525023

BMW 1 Series 1 E81 E87 Petrol N45 N46 Cooling Radiator Water Hose Pipe is an original cooling system component designed for BMW 1 Series petrol engines with N45 and N46 units. Thanks to its factory-fit design tailored to the specific engine bay architecture, it ensures stable coolant flow and proper integration with other components. It is a practical solution for users looking to restore proper coolant circulation without compromising on installation compatibility.

Specifications and technical data

• SKU: 7525023-1
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7525023
• Substitutable numbers: 17127525023, 7525023
• Fuel type: Petrol
• Category: Coolant Hoses

Purpose and function in the cooling system

The presented water hose operates within the coolant circuit of petrol engines, responsible for the controlled flow of fluid between cooling system components. In BMW E81 and E87 vehicles with N45/N46 units, the correct geometry of the hose is crucial for:

• maintaining the proper engine operating temperature,
• preventing local overheating in the cylinder head and block area,
• maintaining the tightness of connections with ports and other hoses,
• stable operation of the thermostat and radiator under full load conditions.

Thanks to its dedicated shape and diameter matched to factory ports, the hose minimizes the risk of kinks and flow restriction, which is particularly important in the tightly packed engine bay of the BMW 1 Series.

Benefits of using an original BMW hose

Using a hose from the Cooling system pipes and hoses group dedicated to a specific BMW model provides a range of practical service and operational benefits:

• factory fit for N45/N46 engines – no need for modifications or diameter adjustments,
• properly selected material stiffness and flexibility, reducing vibrations and hose movement under temperature,
• predictable behavior at high operating temperatures typical of petrol units,
• easier diagnostics of potential leaks due to the preservation of the original cooling line routing.

Choosing such a component is particularly important when addressing issues with overheating, system airlocks, or unstable cabin heating, where every section of the hose affects the overall hydraulics of the circuit.

Component condition and installation aspects

The offered hose is a used part, which in practice means an opportunity for an economical repair while maintaining the original BMW installation specification. Before installation, a standard service procedure is recommended:

• verifying connection surfaces and clamps,
• checking the condition of the ports and any seals,
• properly bleeding the cooling system after replacing the hose.

This approach allows for restoring proper coolant circulation in the petrol engine and reducing the risk of recurring leaks or pressure drops in the system.

Technical support and selection by numbers

The component has a dedicated OEM part number and associated interchangeable numbers, which facilitates precise identification in BMW catalogs and comparison with the currently installed hose. In case of doubts regarding the selection of the component for a specific engine version or model year, it is worth using verification methods based on the OEM number or vehicle data.

For users who want to better understand the impact of a functional coolant circuit on engine durability, the article describing typical overheating problems and radiator maintenance will be helpful – details can be found in the material Engine cooling system – overheating, repair, and used radiators. If you are interested in a practical guide on selecting parts based on OEM numbers or vehicle data, it is worth checking out the guide how to select the right car part by VIN and OEM number.

Related BMW cooling system components

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as additional water pipes, flexible return hoses, or sections connecting to the radiator, check out the available parts in the category BMW cooling system pipes and hoses.