Mercedes W204 W212 OM642 Engine Bleed Pressure Air Valve Breather A6420101291

The Mercedes W204 W212 OM642 Crankcase Ventilation Valve Hose is a component of the crankcase ventilation system designed for OM642 diesel engines, used in popular Mercedes C-Class W204 and E-Class W212 models. This used part from the Hoses, Tubes, and Pipes group allows for the restoration of proper gas circulation in the diesel engine, stabilizing its operation and reducing the risk of unwanted oil leaks. It's a practical solution for users seeking a factory fit without the need to invest in a new part.

Specifications and technical data

• SKU: A6420101291-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420101291
• Substitutable numbers: A6420101291, A 642 010 12 91
• Fuel type: Diesel
• Part type: Hose
• Category: Hoses, Lines & Pipes

Function and Application in the OM642 Engine

The crankcase ventilation valve with hose in the OM642 diesel system is responsible for the controlled removal of gases from the crankcase into the intake system. A properly functioning component:

• stabilizes internal engine pressure,
• limits oil blow-by into the intake,
• supports smooth engine operation under various loads,
• helps maintain the cleanliness of the intake system and turbocharger.

In diesel engines like the OM642, a functional crankcase ventilation hose is crucial for operational refinement, smoke levels, and the durability of other auxiliary components.

Construction and Fit for Mercedes W204 / W212

The presented crankcase ventilation valve with hose has been specifically designed for the architecture of the OM642 unit installed in Mercedes W204 and W212 models. This means factory hose routing, appropriately sized connector diameters, and a geometry tailored to the engine bay of these models.

This solution facilitates installation and minimizes the risk of leaks that could occur when using universal parts. A used component allows for maintaining the original hose path, which is important for both serviceability and thermal considerations (appropriate distance from hot components).

Benefits of Using a Used OEM Part

Choosing a used crankcase ventilation valve with hose for the OM642 diesel engine offers a sensible compromise between cost and functionality. An original part from disassembly typically:

• ensures proper fit with connectors and mounting points in the engine bay,
• maintains the factory gas flow geometry,
• reduces the risk of installation issues common with aftermarket parts of different shapes.

For users who want to restore the correct operation of the crankcase ventilation system without modifying the installation, this is a practical and technically sound solution.

Designed for Diesel Engines

The described hose with crankcase ventilation valve has been developed with diesel-powered engines in mind. The operating characteristics of a diesel engine – higher pressures, different exhaust temperatures, and specific crankcase conditions – require the use of components adapted to such loads.

This ensures the part better withstands typical diesel operating conditions, and the crankcase ventilation system maintains stability over extended periods of use.

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 vacuum hoses, crankcase ventilation hoses, or air intake pipes, check the available parts in the Mercedes Hoses, Tubes, and Pipes category.

For drivers considering broader service work and the selection of used components, it is also worth familiarizing yourself with the guide on the structural and operational differences between standard and sport parts – you will find practical tips in the article Standard vs. Sport Suspension – Construction Differences and Is It Worth Buying Used Suspension Parts?.