Mercedes W251 V251 Bare Engine 642872 642.872 with 99k miles, 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.).

Mercedes W251 V251 Bare Engine 642872 642.872 with 99k miles, WARRANTY is a used, complete engine block with cylinder heads, sold without ancillaries. Designed for R-Class models, it serves as a solid foundation for professional repairs or engine swaps. By maintaining the factory V6 architecture and utilizing a diesel fuel system, this engine block allows for the restoration of original performance parameters while ensuring high operational refinement. It is an ideal solution for workshops and users seeking a technically compatible foundation for further assembly with their existing components.

Specifications and technical data

• SKU: A6420108546
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420108546
• Substitutable numbers: A6420108546, A 642 010 85 46
• Fuel type: Diesel
• Number of cylinders: 6
• Category: Engines
• Engine code: 642872
• Mileage: 59 000

Technical characteristics of the engine block

The presented engine block belongs to the Engines category and represents the family of V6 diesel units used in Mercedes vehicles. The six-cylinder design ensures balanced operation, good flexibility across the entire rev range, and sufficient torque, which is particularly important for heavier bodies such as the W251/V251.

The cylinder layout and block serve as a base for transferring existing ancillaries (turbo, injectors, manifolds, auxiliary equipment) from the previous unit, which allows for maintaining the vehicle's configuration and reducing costs. The Diesel fuel type promotes economical operation and high mechanical durability, provided that proper installation and maintenance are performed.

Purpose and application in Mercedes W251/V251

The bare engine block is intended for applications where the previous unit has suffered mechanical damage (e.g., seizure, cracked block, damaged pistons or cylinders), while the ancillaries remain in a condition suitable for further use. This variant is particularly beneficial for workshops specializing in the Mercedes brand that have the facilities for professional transfer of ancillaries and ECU configuration.

The engine from the 642 family is widely used across the model range, which facilitates the selection of consumables and service parts. At the same time, maintaining the compatibility of the engine code with the vehicle helps to minimize mechanical and electronic compatibility issues, which is crucial for modern powertrains.

Condition, mileage, and benefits of choosing a used engine block

The unit is offered as a used engine block, meaning that components such as the block, heads, and crankshaft assembly serve as a base for further assembly. The declared mileage allows for an assessment of wear in the context of the typical durability of this engine series, and proper preparation before installation (leak test, compression test, cylinder head verification) enables informed planning for future operation.

Choosing a used engine block instead of a full overhaul of a damaged engine often shortens repair time and can be cost-effective, especially when the original block has suffered severe damage. This solution allows for maintaining the factory specifications of the unit while utilizing a proven, original component.

Installation recommendations and parts selection

Before installation, it is recommended to perform a standard package of service activities: replacing seals, checking the timing system, and verifying the lubrication and cooling systems. A professional workshop with the appropriate technical documentation can prepare the engine block for operation to minimize the risk of future failures.

For users considering the purchase of a used powertrain, an expert guide discussing facts and myths related to such components may be useful – more information can be found in the article Why it is worth buying used gearboxes and engines – facts instead of myths, which describes, among other things, the principles of selection by OEM numbers and practical aspects of cost calculation.

Technical support and additional materials

When planning major work on the powertrain, it is worth expanding your knowledge about typical problems of other brands and models to better assess the risks associated with the operation of modern units. A good point of reference is the guide regarding problematic units in a popular model from the Bavarian manufacturer – details can be found in the material Problematic BMW E90 engines: check what can ruin your budget!, which shows how to consciously approach the purchase and service of engines.

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