Mercedes W164 C209 W211 OM642 Diesel Engine Trim Acoustic Cover A6420101667

Visual condition of the part 

The product shows signs of use visible in the photos. 

Mercedes W164 C209 W211 OM642 Diesel Engine Trim Acoustic Cover is an original engine bay component designed for OM642 diesel units. It ensures the engine compartment remains organized, reduces operating noise, and protects sensitive components from contamination. Thanks to its factory-fit design for ML W164, C209, and W211 models with a Diesel engine, installation is precise and predictable.

Specifications and technical data

• SKU: A6420101667-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420101667
• Substitutable numbers: A6420101667, A 642 010 16 67, A6420100167, A 642 010 01 67
• Fuel type: Diesel
• Category: Other Engine Parts

Function and role of the OM642 engine trim acoustic cover

The engine trim acoustic cover in OM642 units performs several important technical tasks. It stabilizes airflow over the engine, which promotes even heat dissipation while limiting the ingress of dust and fine debris into the upper part of the power unit. Additionally, it acts as a sound-dampening element, reducing the characteristic noise of the diesel engine and improving acoustic comfort inside the vehicle.

In the case of OM642 Diesel engines, a properly selected cover also helps keep wiring harnesses, vacuum lines, and other auxiliary components in place, which facilitates maintenance and reduces the risk of accidental mechanical damage during operation.

Compatibility with Mercedes ML W164, C209, W211 models

The presented cover has been designed specifically for the engine bay architecture of Mercedes ML W164, C209, and W211 models equipped with the OM642 unit. This ensures the retention of factory mounting points, proper profiling for the intake manifold, fuel lines, and auxiliary components, as well as compatibility with factory brackets and clips.

Such a fit translates into:

• secure seating of the cover without material stress,
• no interference with engine auxiliary components,
• preservation of the original airflow geometry in the engine bay,
• an aesthetic, organized look for the power unit.

Performance characteristics and installation benefits

Replacing a damaged or missing engine trim acoustic cover in an OM642 has measurable operational benefits. It limits the accumulation of dirt on injection components, wires, and connectors, which promotes stable operation of the fuel system and electronics. Additionally, it improves acoustic insulation, which is particularly noticeable in diesel-powered vehicles, where every dampening element contributes to driving comfort.

The original design intended for OM642 Diesel units allows for the maintenance of factory thermal and mechanical safety standards, and also facilitates potential service work – disassembly and reassembly are carried out according to the manufacturer's procedures, without the need to modify adjacent components.

Component condition and practical application

The engine trim acoustic cover comes from disassembly, which in practice means it is a part with verified functionality, sourced from a vehicle operated under road conditions. This type of component is particularly attractive in situations where the existing cover has cracked, suffered thermal deformation, or was removed during previous repairs. Using an original part from the secondary market allows for the restoration of the factory engine layout while maintaining reasonable costs.

Choosing a used cover is often preferred by users who expect compliance with factory specifications while wanting to avoid fitment issues typical of universal aftermarket replacements.

Expanding your Mercedes engine bay upgrade

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as additional covers, mounts, or engine bay trim elements, check out the available parts in the Other Mercedes category.

For drivers interested in comparing technical solutions used in high-performance power units, we recommend an article describing the differences in the construction of engines, braking systems, and chassis in high-performance models – details can be found in the post Audi RS vs other models – what is hidden under the hood and chassis?, which helps to better understand the importance of properly selected components in the entire drivetrain.