Mercedes A W168 A140 E14 M166 166940 82HP Complete Engine OM 166.940 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.

Mercedes A W168 A140 E14 M166 166940 82HP Complete Engine OM 166.940 WARRANTY is a factory-spec power unit designed for the W168 A-Class models, offering a proven design and predictable performance parameters. The four-cylinder layout, powered by petrol, ensures smooth, consistent characteristics and good refinement for daily use. This is an ideal solution for users looking for a complete engine for replacement without the need to source individual accessories separately.

Specifications and technical data

• SKU: A1660101700-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1660101700
• Substitutable numbers: A1660101700, A 1660101700, A 166 010 17 00
• Fuel type: Petrol
• Number of cylinders: 4
• Category: Engines
• Mileage: 59 000

Technical characteristics of the M166 unit

The engine belongs to the M166 family used in the first-generation Mercedes A-Class, designed with a focus on compact packaging and a safe crumple zone. The four-cylinder, four-stroke, petrol-powered layout provides linear power delivery and predictable throttle response, which is particularly important in urban traffic.

The unit was engineered as a transverse engine, working in harmony with the W168's characteristic chassis architecture. As a result, it integrates well with factory mounts, the cooling system, and the vehicle's electrical installation, facilitating installation in place of a worn or damaged engine.

Purpose and application in the Mercedes A W168 A140

The presented complete engine is dedicated to the A140 version, where it is responsible for powering the lightweight, urban A-Class body. The design of the unit has been optimized for daily operation, with an emphasis on stable performance across a wide range of loads and predictable behavior in typical road conditions.

The petrol engine works well with the factory gearboxes used in this model, and the four-cylinder configuration simplifies maintenance and diagnostics. This makes it a practical solution both for standard engine replacement and for post-accident repairs when a complete drivetrain swap is necessary.

Benefits of installing a complete used engine

Choosing a complete engine from this series reduces the time and scope of workshop work, as many accessories are already integrated with the unit. This makes it easier to match with the existing installation in the car and reduces the risk of component incompatibility. For workshops, this means more efficient job completion, and for the user – a faster return of the vehicle to full operational status.

The unit comes from the Engines category, which means it is a key element for restoring the full functionality of the drivetrain. A used engine of this generation, with proper installation and appropriate maintenance, can provide a long service life in daily use.

Engine selection and the risk of failure – a practical approach

When choosing a used engine, it is worth considering not only model compatibility but also the actual technical condition of the unit and its service history. A properly selected complete petrol engine helps avoid typical problems associated with incompatible accessories or differences in wiring harnesses.

For a comparison of how manufacturers approach engine design and typical operational problems, it is worth reading our guide on another popular brand – faulty BMW E90 engines and their most common failures. This allows for a better understanding of what to look for when buying a used engine and how to minimize the risk of costly repairs.

Drivetrain expansion and related components

Replacing the power unit is often associated with inspecting other drivetrain components, such as the differential, half-shafts, or control elements. In the case of high-mileage cars, it is worth considering a diagnosis of the entire drivetrain to avoid a situation where a newly installed engine works with excessively worn components.

If you want to better prepare for assessing the condition of these elements and plan repairs consciously, our guide on the secondary market may be helpful – used differentials and drivetrain components – what to look for. This is a practical supplement to your knowledge for major drivetrain work.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other parts from the same group, such as blocks, cylinder heads, or complete power units, check out the available parts in the Mercedes Engines category.