BMW 3 Series E90 320si N45 173HP Complete Engine N45B20A WARRANTY

Warranty and technical condition of the part

The engine is sold with a 90-day warranty.

The warranty covers the engine itself; engine accessories are covered by a 30-day warranty.

The power unit was tested before removal and is in full working order.

Listing details

The offer applies to a complete engine.

The engine comes from a right-hand drive (RHD) vehicle. The wiring harness is not compatible with left-hand drive (LHD) vehicles and requires replacement or modification.

BMW 3 Series E90 320si N45 173HP Complete Engine N45B20A WARRANTY is a complete powertrain unit from the N45 family, designed for the petrol 320si version. The engine belongs to the Engines category and is an attractive solution for users looking for a technically compatible, proven powertrain for the BMW 3 Series E90.

Specifications and technical data

• SKU: 0404479-2
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 0404479
• Substitutable numbers: 11000404479, 0404479, 11000404480, 0404480
• Fuel type: Petrol
• Number of cylinders: 4
• Category: Engines
• Mileage: 59 000

Technical characteristics of the N45B20A unit

The presented engine is a four-cylinder petrol unit from the N45 family, developed specifically for the 320si version. The design, based on an inline 4-cylinder layout, ensures a good balance between performance and refinement, while the high-output configuration of this variant allows for power characteristic of sport-tuned BMW 3 Series versions.

The N45B20A unit is known for its high operating revs and dynamic characteristics, which translates into quick throttle response and precise power delivery. The use of a petrol fuel system promotes smooth operation across the entire rev range, and a properly selected configuration of accessories allows for effective utilization of the engine's potential in daily use and during more demanding driving.

Purpose and application in the BMW E90 320si

The engine was designed as a unit dedicated to the BMW 3 Series E90 in the 320si version, which means full structural compatibility with factory mounting points, the drivetrain, and the vehicle's electrical system. As a result, it provides a proper base for:

• comprehensive replacement of a damaged powertrain unit,
• professional repair following a mechanical engine failure,
• restoring the original driving parameters of the 320si version.

The four-cylinder configuration combined with petrol power allows maintaining the 320si's characteristic combination of front-end lightness, precise handling, and dynamic acceleration, which is particularly important for drivers who value the sporty character of BMW.

Condition, mileage, and benefits of choosing a used engine

The offered engine is in Used condition, meaning it comes from an operated vehicle but retains functionality suitable for further use after proper installation and any necessary preparatory service. The declared mileage of the unit is relatively low for this generation, which is a significant advantage in terms of the remaining service life of mechanical components.

Choosing a complete, used engine from the Engines category allows for significantly reducing repair costs compared to purchasing a brand-new unit, while maintaining the original BMW design specifications. For workshops and individual users, this means a favorable compromise between price, repair time, and maintaining the vehicle's factory parameters.

Compatibility, part numbers, and identification

The engine has an assigned OEM part number and associated interchangeable numbers, which facilitates unambiguous identification of the unit in BMW catalogs and parts selection systems. This allows for precise verification of compatibility with a specific equipment version and model year of the BMW E90 320si, minimizing the risk of selecting an incorrect component.

Additionally, the product is marked with an individual SKU, which streamlines order processing and communication with the store's technical department or the installing workshop. If necessary, it is possible to quickly compare catalog data, such as fuel type or number of cylinders, with the requirements of a specific vehicle.

Installation recommendations and additional information

Before installation, it is recommended to perform standard preparatory procedures, such as leak testing, accessory verification, replacement of consumables, and adjusting the configuration to the specific BMW E90 unit. Professional installation at a specialized service center allows for fully utilizing the potential of this unit and limiting the risk of improper operation after replacement.

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 blocks, heads, or complete powertrains, check the available parts in the BMW Engines category.

To better understand the specifics of the powertrains used in the 3 Series and to consciously plan your repair budget, it is worth reading the guide on typical problems and costly failures in this model: Troublesome BMW E90 engines: check what can ruin your budget!

If you want to further optimize service costs while also caring for the environment, the material describing the benefits of reusing components may also be helpful: Eco-driving: discover the benefits of used car parts.