BMW E90 320si N45 173HP Bare Engine N45B20A with New Timing Installed WARRANTY

Warranty and technical condition of the part

The engine is sold with a 90-day warranty.

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

Listing details

The offer applies to a bare engine.

The engine is sold without accessories (e.g. alternator, starter motor, manifolds, injectors, turbocharger, etc.).

BMW E90 320si N45 173HP Bare Engine N45B20A with New Timing Installed WARRANTY is a used, complete bare engine block of a petrol unit, prepared for precise replacement in the BMW E90 320si model. Thanks to the installation of a new timing system, it serves as an attractive base for professional repair or rebuilding of the powertrain in cars of this series. This is a solution for users looking for a technically refined engine with a sporty character, while maintaining the factory specifications of the 320si version.

Specifications and technical data

• SKU: 0404479-1
• 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: 65 000

Technical characteristics of the N45B20A bare engine

The presented bare engine belongs to the Engines category and is intended for the N45B20A unit used in the BMW E90 320si. The four-cylinder inline design ensures smooth operation and good refinement at higher RPMs, which is particularly important in versions with a sportier setup. The engine runs on petrol, allowing for dynamic power delivery and quick throttle response, typical for this generation of BMW units.

A bare engine means you receive a base block with a cylinder head, prepared for further assembly with accessories compatible with your specific E90 320si configuration. This form is beneficial both for post-accident repairs and for replacing a worn-out unit with a verified, used component of known origin.

New timing system and benefits of installation

A key advantage of this engine is the new timing system, which significantly reduces the risk of typical failures associated with the wear of the chain, tensioners, or timing gears. For the user, this means:

• increased reliability of the unit after installation,
• lower risk of costly failures in the short term after replacement,
• more stable operating parameters at high RPMs characteristic of the 320si.

The four-cylinder petrol engine fits well into the concept of a lightweight, high-revving unit, and the use of a fresh timing system improves operational predictability. This is especially important for cars driven dynamically, where the precision of timing phases has a direct impact on performance and operating culture.

Purpose, mileage, and application in the BMW E90 320si

The offered bare engine is dedicated to the BMW 3 Series E90 in the 320si version, where maintaining the original characteristics of the N45 unit is essential. The used nature of the product, with the mileage documented in the specification, allows for a rational balance between purchase cost and expected durability. This type of engine will work well both for repairs of daily-driven vehicles and in projects focused on maintaining the originality of the 320si version.

The four-cylinder petrol unit is a good choice for drivers who expect linear power delivery, predictable throttle response, and easier diagnostics compared to more complex multi-cylinder designs. The bare engine allows for the transfer of accessories from the previous engine, which facilitates matching it to the specific configuration of the car.

Why choose a used BMW N45 bare engine

Choosing a used bare engine with a new timing system is a reasonable compromise between cost and operational safety. You gain:

• an original design intended for the BMW E90 320si,
• the possibility of using existing accessories from your car,
• reduced risk of timing failure thanks to its replacement before sale.

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 blocks, heads, or complete power units, check out the available parts in the BMW Engines category.

To better understand the specifics of the power units in this model and plan your repair consciously, it is worth reading the guide on our blog: Troublesome BMW E90 engines: check what can ruin your budget!. Additionally, if you are interested in the broader context of the premium car parts market and want to optimally use the potential of used components, also read the article Crisis in the new parts market? Why in 2026 used originals for premium cars (BMW, Mercedes, Porsche) are the hottest trend.

Summary

BMW E90 320si N45 173HP Bare Engine N45B20A with New Timing Installed WARRANTY is a technically refined proposal for users who want to restore full powertrain efficiency while maintaining the character of the original unit. A used bare engine with a new timing system provides a solid base for professional installation, allowing you to limit the risk of typical failures and maintain proper engine operating parameters in a demanding model such as the BMW E90 320si.