Mercedes W204 C207 W212 W205 W213 M274 Petrol Belt Tensioner A2742000070

Mercedes W204 C207 W212 W205 W213 M274 Petrol Belt Tensioner is an original component from the Tensioner and Idler Pulleys group, designed for M274 petrol engines in popular C-Class, E-Class, and other series models. The used belt tensioner ensures proper guidance of engine accessories, stabilizing the operation of the multi-ribbed belt and reducing the risk of slippage and noise.

Specifications and technical data

• SKU: A2742000470-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2742000470
• Substitutable numbers: A2742000470, A 274 200 04 70, A2742000070, A 274 200 00 70
• Fuel type: Petrol
• Category: Idlers & Tensioners

Purpose and function in the accessory drive system

The belt tensioner in the M274 petrol engine is responsible for maintaining the correct tension of the belt driving key components, such as the alternator or air conditioning compressor. Stable belt tension translates into smooth operation of the accessories, reduced vibration, and lower load on the bearings. In Mercedes W204, C207, W212, W205, and W213 series vehicles, a properly functioning tensioner is essential for the engine's performance and the durability of the entire system.

Benefits of using an original Mercedes component

Choosing a tensioner from the Mercedes range means maintaining the factory operating parameters of the accessory drive system. The OEM component is designed for a specific engine type and load range, which ensures that it:

• provides the correct belt routing geometry,
• maintains stable tension across the entire RPM range,
• reduces the risk of squealing, jerking, and uneven accessory operation,
• facilitates diagnostics – operating parameters match factory specifications.

For Petrol engines, using a dedicated tensioner is particularly important due to higher operating speeds and greater sensitivity to incorrect belt tension.

Characteristics of the used belt tensioner

The offered component comes from dismantling and is used, which allows for lower service costs while maintaining the manufacturer's original specifications. Used tensioner and idler pulleys are a popular choice in situations where:

• compatibility with the factory mounting and belt routing system is essential,
• a quick replacement is needed without the need for accessory modifications,
• optimizing repair costs while using OEM parts is important.

The belt tensioner for the M274 unit is structurally matched to the specific accessory drive system in the listed Mercedes generations, which facilitates installation and reduces vehicle downtime.

Selection and application in service practice

When selecting a tensioner for a Mercedes with an M274 engine, it is crucial to match it to the body version and engine type, so it is worth verifying compatibility with the vehicle's documentation before installation. Replacing the tensioner is recommended, among other things, when:

• there are noticeable vibrations or noise from the accessory belt area,
• there are visible signs of wear on the pulley's working surface,
• a belt and pulley replacement is planned as part of preventive maintenance.

Using an original element from the Tensioner and Idler Pulleys group helps restore proper belt operating conditions, which affects the longevity of the accessories and the comfort of using the car.

Service expansion and related components

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 guide pulleys, idler pulleys, or auxiliary tensioners, check the available parts in the Mercedes Tensioner and Idler Pulleys category.

When planning a repair using dismantled parts, it is also worth learning about the principles of service cost optimization and making informed choices regarding used OEM components – you can find practical tips in the article Rising repair costs and the boom in used parts – how to save on car service?.