BMW 3 Series E46 318i 318Ci 318ti Petrol N42 143HP Bare Engine N42B20A 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 3 Series E46 318i 318Ci 318ti Petrol N42 143HP Bare Engine N42B20A WARRANTY is a short block prepared for 3 Series owners who need a technically compatible power unit for professional repair. This solution allows for the use of existing auxiliary equipment and the preservation of factory performance characteristics, while reducing costs compared to a complete engine. Thanks to this, you can carry out a precise powertrain rebuild while maintaining compliance with the original BMW specification.

Specifications and technical data

• SKU: 0391085
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 0391085
• Substitutable numbers: 11000391085, 0391085, 11000304935, 11007519601, 11007516422, 11000391086, 11000304936, 11007519602, 11007516423, 0304935, 7519601, 7516422, 0391086, 0304936, 7519602, 7516423
• Fuel type: Petrol
• Number of cylinders: 4
• Category: Engines
• Mileage: 59 000

Purpose and compatibility

The offered short block is intended for BMW 3 Series E46 318i, 318Ci, and 318ti models with the 143 HP N42 petrol engine. The design of the N42B20A unit was developed for dynamic yet economical driving, which fits well with the character of the lightweight 3 Series versions. The bare engine serves as a base for transferring the accessories from your current motor, which facilitates maintaining full compatibility with the electrical installation, ECU, and exhaust system of your specific vehicle.

Construction and technical characteristics

The N42B20A unit is a modern, inline four-cylinder petrol engine designed for smooth operation in the mid-RPM range. The use of a four-cylinder layout helps reduce the weight of the vehicle's front end, which improves handling and steering response. As a bare short block, the engine provides a solid base for further assembly of accessories, allowing the mechanic to precisely match all components to the specific car configuration.

The mileage of the unit is limited, which in practice means less wear on moving parts and a better starting point for further operation after proper installation and servicing. As a result, this engine can be an attractive alternative to rebuilding a heavily worn motor.

Application in service practice

The N42B20A bare short block will work particularly well in situations where the existing engine has suffered a major mechanical failure (e.g., damage to the block, crankshaft, or cylinder head), but the accessories remain in a condition suitable for further use. Such a scenario allows you to:

• reduce repair costs by reusing functional accessory components,
• maintain compliance with the factory vehicle configuration,
• shorten workshop turnaround time by retaining original wiring harnesses and ECUs.

The petrol-powered engine works well with factory BMW control systems, ensuring predictable performance parameters after proper installation and adaptation.

Condition, verification, and installation recommendations

The unit comes from the Engines category and is offered as a used component, which in practice means the necessity of professional assessment before installation and performing standard service procedures (replacement of fluids, service seals, timing check). This preparation method allows you to maximize the potential of the short block and reduce the risk of subsequent service downtime.

Before installation, it is recommended to have the workshop:

• check the oil system and cooling system for leaks,
• verify cylinder compression,
• check the condition of spark plug sockets and mounting threads for accessories.

Thanks to this, the engine can become a solid base for further operation in your BMW E46, without the need to invest in a complete, new power unit.

Selection of other components from the BMW Engines group

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 short blocks, engine blocks, or cylinder heads, check out the available parts in the BMW Engines category.

Technical support and knowledge about BMW units

When choosing a used engine for a BMW, it is worth knowing the typical issues of specific generations and designs to consciously plan the scope of service work. Practical information about problematic power units of this brand can be found in the article: Troublesome BMW E90 engines: check what can ruin your budget!. This is a valuable addition to your knowledge when making a decision to invest in a used power unit.