Mercedes W205 W213 M274 Coolant Reservoir Expansion Tank Petrol A2742000385

Mercedes W205 W213 M274 Coolant Reservoir Expansion Tank is a factory cooling system component designed for M274 series petrol engines in C-Class (W205) and E-Class (W213) models. This used expansion tank ensures stable engine operating conditions by supporting safe discharge of excess coolant and maintaining proper system pressure.

Specifications and technical data

• SKU: A2742000385
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2742000385
• Substitutable numbers: A2742000385, A 274 200 03 85
• Fuel type: Petrol
• Category: Expansion & Overflow Tanks

Function and role in the cooling system

The expansion tank in the M274 petrol engine is responsible for compensating for changes in coolant volume resulting from temperature fluctuations. A properly selected component:

• stabilizes pressure in the cooling system during engine operation,
• allows for easy coolant level monitoring and quick refilling,
• reduces the risk of engine overheating,
• supports uniform heat dissipation from the engine block and accessories.

Thanks to its proper design, the tank works in harmony with other cooling system components, which translates into stable engine operating temperature and predictable vehicle performance under various operating conditions.

Designed for M274 petrol engines

The presented expansion tank is dedicated to petrol engines, which is significant for the thermal and pressure characteristics of the entire system. For M274 units, using the correct tank:

• ensures compatibility with the factory hose and mounting system,
• facilitates installation without the need for structural modifications,
• maintains compliance with the operating parameters specified by the manufacturer.

Selecting a component compatible with the engine unit is crucial for maintaining cooling system reliability and reducing the risk of leaks or improper operation of the thermostat and water pump.

Condition, application, and benefits of installation

The offered expansion tank comes from the used parts segment, allowing for an economical repair of the cooling system while maintaining the original design. This type of solution is particularly beneficial when:

• the existing tank shows signs of cracks or leaks,
• coolant loss occurs in the system,
• replacement of the component is necessary after engine overheating.

Choosing an original salvaged tank allows you to maintain factory fitment for the cooling system, which minimizes installation time and the risk of operational issues after replacement.

Application in service practice and tuning

Replacing the expansion tank is often performed during comprehensive service work in the engine bay, such as repairs after cooling system failure or upgrades related to improving reliability. In projects where used components are utilized, it is worth paying attention to selecting elements compatible with the specific engine unit and vehicle model. Additional tips on safely using second-hand parts can be found in the article Buying used car parts – common mistakes when choosing tuning parts, which helps in consciously planning modifications and repairs.

System expansion within the same parts group

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 additional tanks, mounting hardware, or related cooling system components, check the available parts in the Mercedes expansion tanks category.