BMW 3 Series E90 320si N45 Coolant Hose Connector 7559333

The BMW E90 320si N45 Water Hose Connector is an original cooling system component designed for the special N45 engine version of the 320si. This connector allows for a technically correct rebuild of the coolant circuit while maintaining the factory geometry and fit typical of BMW solutions.

Specifications and technical data

• SKU: 7559335
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7559335
• Substitutable numbers: 11537559335, 7559335, 7559333, 11537553973, 7553973
• Category: Turbos & Parts

Purpose and function in the cooling system

The BMW E90 320si N45 water hose connector is responsible for stable coolant flow between engine and accessory components. A properly selected component ensures:

• tight connection of water pipes in the sensitive area of unit N45,
• maintaining the correct direction of coolant flow,
• reducing the risk of leaks and engine overheating,
• maintaining correct thermal parameters in everyday and dynamic operating conditions.

Due to the specific nature of the 320si version, the use of the correct connector is important both for the durability of the drive unit and the operational stability of the entire cooling system.

Original origin and fit

The component comes from the BMW OE line, meaning it's factory-fitted to the N45 engine design in the E90 320si. In practice, this translates to:

• maintaining the original nozzle geometry and connection diameters,
• secure fit with factory water lines and mountings,
• compliance with the OEM part number and related interchangeable numbers, which can be verified in the technical specifications or by the VIN.

Thanks to this, the connector can be used as a replacement element in service repairs, without the need to modify the cooling system.

Used condition and technical aspects of assembly

The connector offered is in used condition, allowing for a cost-effective repair while maintaining the original BMW design. Standard preparatory steps are recommended before installation:

• inspection of sealing surfaces and sockets for clamps or connectors,
• verification of possible traces of corrosion or mechanical damage,
• selection of new seals and clamps compatible with the cooling system of a given vehicle.

A correctly installed connector supports the stable operation of the turbocharger and engine accessories, as maintaining the correct operating temperature is crucial for the durability of the entire drive system.

Benefits of using the original water connection

The use of the original BMW E90 320si N45 water hose connector brings a number of practical service and operational benefits:

• reliable fit to a specific version of the N45 engine without the risk of collision with other accessories,
• maintaining the factory concept of coolant circulation,
• Possibility of verification by OEM number and replaceable numbers in BMW catalogues or parts selection systems,
• consistency with the turbocharger and parts category, where proper cooling has a direct impact on the durability of the charging system.

This solution is particularly beneficial for users who want to keep their car in a configuration close to the factory one, without using substitutes with an uncertain fit.

Parts selection and additional technical information

When selecting a connector for a BMW E90 320si with an N45 engine, it's best to rely on the OEM part number, reference numbers, and data from the manufacturer's catalog or service documentation. If in doubt, it's recommended to compare the shape and connection points with the component removed from the vehicle.

If you're wondering whether an original, aftermarket, or used part is the better choice for you, this article describing the differences in cost, quality, and fit may be helpful. Check out our detailed comparison article: original, aftermarket, and used car parts – which offers the best value .

Other BMW cooling system connectors and components

If you are also looking for other water pipe connectors and components related to the supercharging system in cars of this brand, check out the dedicated category of turbochargers and BMW parts in our store: turbochargers and BMW parts .