Mercedes W164 W211 OM629 EGR Valve Exhaust Recirculation Pipe A6291400408

Mercedes W164 W211 OM629 EGR Valve Exhaust Recirculation Pipe is an exhaust gas recirculation system component designed for diesel engines, supporting the proper operation of the power unit and reducing exhaust emissions. As a part from the EGR Valves and Parts group, it is responsible for stable exhaust gas flow in the secondary circuit, which is significant for both performance and engine durability. Using an OEM component allows for a technically correct replacement of a worn-out element without interfering with the factory design.

Specifications and technical data

• SKU: A6291400408
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6291400408
• Substitutable numbers: A6291400408, A 629 140 04 08
• Fuel type: Diesel
• Category: EGR Parts & Valves

Purpose and function in the EGR system

The described EGR valve housing and pipe works with the diesel engine, directing a portion of the exhaust gases back to the intake manifold. As a result, the system reduces combustion temperature and nitrogen oxide levels, which translates into more stable operation of the power unit. The design, matched to the architecture of the OM629 engine in Mercedes W164 and W211 models, ensures proper medium flow and connection tightness.

This element is particularly important in vehicles operated in urban conditions, where frequent start cycles and low loads promote carbon deposit buildup. Replacing a worn or leaking EGR housing with a functional component allows for restoring proper exhaust flow, reducing engine control unit errors, and minimizing the risk of the unit entering limp mode.

Benefits of using an original EGR housing

Using an original element from the EGR Valves and Parts group ensures a proper fit to the factory intake and exhaust system. The appropriate channel geometry, connection diameters, and mounting points allow for installation without modifications, which shortens service time and reduces the risk of leaks. For a diesel engine, this means stable operating parameters, predictable exhaust gas recirculation values, and correct cooperation with the control unit software.

A used OEM component is also a cost-effective solution while maintaining high manufacturing quality. In many cases, it allows for restoring full functionality of the EGR system without the need to invest in a complete new set. This is a practical solution for users who want to keep their car in good technical condition while maintaining a reasonable repair budget.

Installation and operational aspects

The EGR valve housing and pipe in this Mercedes model is a component operating at elevated temperatures and in an exhaust gas environment, which is why it is crucial to maintain proper connection tightness and correct positioning relative to other components. During installation, it is recommended to:

• verify the condition of seals and mounting clamps,
• check the cleanliness of intake and exhaust channels,
• check the correct seating of the element relative to the manifold and lines.

After proper installation, the exhaust gas recirculation system should work evenly, without leaks or unwanted noises, and the engine control unit should not register errors related to EGR flow. This translates into smoother power unit operation, stable idle speed, and predictable reactions to load.

Part selection by OEM number and compatibility

When selecting this EGR housing for a specific Mercedes vehicle, it is crucial to compare the OEM number and vehicle data, such as engine type and body generation. This allows avoiding installation problems and ensures full compliance with the factory configuration. In case of doubt, it is worth using the VIN number and service documentation to confirm the correct variant of the element.

To facilitate the verification process, a practical guide has been prepared describing step-by-step how to check the compatibility of used components with a specific car. Detailed tips, examples, and a list of questions for the seller can be found in the article Guide: how to select the right car part by VIN and OEM number, which helps reduce the risk of purchasing an incompatible element.

Expansion of the EGR system in Mercedes

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 recirculation pipes, exhaust gas coolers, or valve bodies, check the available parts in the Mercedes EGR Valves and Parts category.