Mercedes ML W166 Fuel Tank Reservoir OM651 OM652 Diesel A1664705601

Mercedes ML W166 Fuel Tank Reservoir OM651 OM652 is an original fuel system component designed for diesel engines in the ML W166 series. Thanks to its factory origin, it ensures proper compatibility with OM651 and OM652 units and provides stable diesel fuel supply to the engine under typical operating conditions of a Mercedes SUV.

Specifications and technical data

• SKU: A1664705601
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1664705601
• Substitutable numbers: A1664705601, A 166 470 56 01
• Fuel type: Diesel
• Category: Fuel Tanks & Filler Necks

Purpose and function in the fuel system

The presented reservoir is a component from the Fuel tanks and filler pipes group, responsible for the safe storage of diesel fuel and its stable delivery to the supply system. The design, adapted for diesel engines in the Mercedes ML W166, allows for maintaining the appropriate fuel level under various load conditions, which is crucial for the operation of the injection system and the protection of the high-pressure pump.

Being dedicated to OM651 and OM652 units means that the reservoir's geometry, the arrangement of ports, and the internal architecture of the chambers are matched to the specifics of these engines, which reduces the risk of air entering the system and starting problems at low fuel levels.

Benefits of using an original Mercedes reservoir

Using an original fuel reservoir in a Mercedes ML W166 translates into a number of practical benefits:

• preservation of the factory geometry and working capacity of the fuel system,
• proper fitment to body mounts and fuel line routing,
• compatibility with equipment mounted inside the reservoir (e.g., pump module, level sensors),
• reduction of the risk of leaks and deformations characteristic of lower-quality replacements.

For vehicles with a diesel engine, stability of the diesel fuel supply is crucial for the durability of the injectors and the pump, which is why choosing the right reservoir has a direct impact on long-term operating costs.

Performance characteristics and installation

The offered component comes from a Mercedes vehicle and is intended for re-installation as a used part. In practice, this means maintaining the original design, which was engineered for the specific loads and operating conditions of the ML W166 diesel SUV. Replacing the reservoir is a typical repair step in cases of mechanical damage, corrosion, or leakage issues.

Compared to universal solutions, the original reservoir for the ML W166 facilitates the mechanic's work thanks to its predictable fitment to factory mounting points and correct routing of filler pipes and fuel lines. This allows for shorter installation time and reduces the risk of subsequent leaks or assembly errors.

Significance for diagnostics and fuel system durability

In modern diesel units, any disruptions in fuel supply can result in controller errors, power loss, or uneven engine operation. A functional fuel reservoir, properly selected for the ML W166 model, helps maintain stable operating conditions for the injection system, which is important for both performance and exhaust emissions.

To better understand the relationships between the reservoir, pump, and injectors, and to properly approach diagnostics and part selection by OEM number, it is worth checking out our guide: Fuel system – injectors, pumps, and fuel reservoir: maintenance and regeneration. The article discusses practical aspects of operating and regenerating fuel supply components, which facilitates making an informed service decision.

Application in service practice and part selection

When repairing the fuel system in a Mercedes ML W166 with a diesel engine, the selection of the appropriate reservoir should be based on vehicle data and part numbers, which minimizes the risk of incompatibility. The original component from the Fuel tanks and filler pipes group allows for maintaining the structural integrity of the entire system, which is particularly important during intensive use or operation in more demanding conditions.

If you are planning a comprehensive repair or upgrade of the fuel system area in your Mercedes and need other components from the same group, such as filler pipes, breather hoses, or additional mounting elements, check the available parts in the Mercedes fuel tanks and filler pipes category.