The Mercedes W204 W212 OM642 Diesel Fuel Rail is a fuel system component designed for OM642 diesel engines in Mercedes W204 and W212 class vehicles. It is responsible for the stable distribution of high-pressure fuel to the injectors, which is crucial for the engine's smooth operation, performance, and fuel consumption.
Specifications and technical data
- SKU: A6420702995
- Mark: Mercedes (Genuine OE)
- Condition: Used
- OEM Part Number: A6420702995
- Substitutable numbers: A6420702995, A 642 070 29 95, A6420700146, A 642 070 01 46, BG
- Fuel type: Diesel
- Category: Fuel Injectors
Purpose and Function of the Fuel Rail
In a diesel engine, the fuel rail acts as a common high-pressure manifold from which individual injectors are supplied. In OM642 units, using a properly selected fuel rail allows for:
- maintaining stable fuel pressure across the entire engine load range,
- precise dosing of diesel fuel to each cylinder,
- reducing vibrations and pressure pulsations in the common rail system,
- improving the smooth operation of the diesel engine and reducing combustion noise.
Thanks to the proper functioning of the fuel rail, the fuel supply system is more predictable, and the engine control unit can more accurately control injection timing and fuel quantity.
Compatibility with OM642 Engine
The presented fuel rail is designed to work with the OM642 diesel engine, widely used in Mercedes W204 and W212 models. Using a component from the same design family as the factory part means:
- maintaining the original operating characteristics of the injection system,
- correct geometric fit to the cylinder head and high-pressure lines,
- compatibility with the factory engine control unit and pressure sensors.
This solution is recommended wherever maintaining parameters close to factory specifications is desired without the need for fuel system modifications.
Category: Injector Nozzles and the Role of the Fuel Rail
Although the product is assigned to the Injector Nozzles category, in practice, it is a key component that works with injectors in a common rail system. A properly selected fuel rail:
- stabilizes the operating conditions of the injector nozzles, which translates to even fuel atomization,
- reduces the risk of overflows and uneven operation of individual cylinders,
- supports the maintenance of correct exhaust emission parameters in a diesel engine.
In case of problems with common rail system pressure or uneven engine operation, it is worth considering diagnostics of both the injectors and the fuel rail.
Used Condition and Advantages of OEM Parts
The offered fuel rail is an original Mercedes brand component in used condition. In practice, this means:
- maintaining factory geometry and quality of workmanship,
- reliable fit to the fuel system without the need for modifications,
- attractive cost-to-functionality ratio compared to new aftermarket parts.
For workshops and users seeking a cost-effective solution while maintaining OEM standards, a used fuel rail is a practical choice.
Diesel Injection System Diagnostics
When replacing the fuel rail, it is also worth assessing the condition of the injectors and the entire common rail system. If you want to better understand the typical symptoms and consequences of fuel supply problems, check out the article: Diesel Injector Failures – How to Recognize Them and What Neglecting Them Entails. This is a practical addition to your knowledge when planning a diesel engine repair.
Other Mercedes Injector Nozzles
If you are looking for other Mercedes injector nozzles suitable for a specific model or engine variant, check out our dedicated category: Mercedes injector nozzles. There you will find a wide selection of fuel system components for various diesel engines of this brand.
To better plan repairs and reduce vehicle downtime, you can also consult the guide on the availability of used OEM parts: How the immediate availability of used OEM parts affects repair time. This is a helpful source of information for workshops and users who value efficient service.
