Mercedes W168 OM668 668.940 Diesel Fuel Injector Rail Line A6680700095

The Mercedes W168 OM668 fuel rail is a component of the diesel engine fuel system, designed for diesel units in W168 A-Class models. It is responsible for the stable distribution of fuel to the injectors, which is crucial for engine smoothness, performance, and fuel consumption.

Specifications and technical data

• SKU: A6680700095
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6680700095
• Substitutable numbers: A6680700095, A 668 070 00 95, 0445214005, 0 445 214 005
• Fuel type: Diesel
• Category: Fuel Injectors

Purpose and Role in the Common Rail System

The fuel rail in the OM668 engine functions as a pressure accumulator in the Common Rail system. It enables precise diesel fuel metering to individual injectors, stabilizing pressure throughout the system. A correctly selected fuel rail is essential for the engine control unit to maintain proper injection parameters across the full range of loads and speeds.

Using a fuel rail dedicated to a specific engine type minimizes the risk of starting problems, power loss, or uneven idling. For Mercedes diesel engines, the correct selection of fuel injection system components directly impacts the durability of the entire fuel system.

Benefits of Using an Original Fuel Rail

Choosing a fuel rail matched to the OM668 engine allows for the preservation of the engine's factory operating parameters. The main advantages of such a solution include:

• Stable fuel pressure across the entire RPM range, promoting smooth engine operation.
• Better control of the combustion process, thereby reducing smoke and power loss.
• Compatibility with the factory engine control unit without the need for software modifications.
• Reduced risk of injector overload due to the rail's appropriate hydraulic characteristics.

For workshops and users, this means easier diagnostics, predictable vehicle behavior, and the ability to maintain near-factory parameters without costly modifications.

Application in the Diesel Injection System

The fuel rail in a diesel engine is particularly sensitive to fuel quality and the condition of other system components. For Mercedes A-Class W168 units, a properly functioning fuel rail supports:

• correct formation of the injection dose in various operating modes (starting, load, engine braking),
• maintenance of appropriate operating pressure for the injectors, which translates to engine smoothness,
• reduction of vibrations and noise typical for older generation diesel units.

When replacing the fuel rail, it is advisable to check the condition of the injectors and other Common Rail system components to avoid the recurrence of the same faults after a short period of operation.

Condition, Installation, and Service Aspects

The offered fuel rail is a component from the Injector Nozzles category, sourced from disassembly. This type of part allows for economical repair of the fuel system while maintaining compliance with factory specifications. Before installation, standard service procedures are recommended: cleaning fuel lines, verifying seals, and checking system operating parameters on a diagnostic bench.

For the proper functioning of the injection system, it is also important to use fuel of appropriate quality and regularly replace the fuel filter, which reduces the risk of contamination of the fuel rail and injectors.

Technical Support and Educational Materials

If you want to better understand how problems with diesel injection systems manifest, it is worth reading the article Diesel Injector Faults – How to Recognize Them and What Their Neglect Entails. This is a practical source of knowledge for mechanics and owners of diesel-powered vehicles.

If you are looking for other Mercedes Injector Nozzles suitable for various models of this brand, check out our dedicated category: Mercedes Injector Nozzles. This will allow you to easily compare available solutions and select the right component for your specific engine.