Mercedes W169 W245 OM640 Diesel Thermostat Coolant Housing A6402000515

Mercedes W169 W245 OM640 Diesel Thermostat Coolant Housing is a component from the Thermostats and housings group, designed for OM640 diesel engines in compact Mercedes A-Class (W169) and B-Class (W245) models. It is responsible for precise coolant temperature control in Diesel units, which ensures stable engine operation and proper thermal characteristics of the system.

Specifications and technical data

• SKU: A6402000515
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6402000515
• Substitutable numbers: A6402000515, A 640 200 05 15, A6402000415, A 640 200 04 15
• Fuel type: Diesel
• Category: Thermostats & Housings

Purpose and function in the cooling system

The thermostat in the OM640 engine controls the circulation of coolant between the engine block and the radiator, maintaining an optimal operating temperature range. In Mercedes diesel units, a properly functioning thermostat is crucial for:

• stabilizing engine operating temperature in both city and highway driving conditions,
• reducing fuel consumption in the Diesel engine,
• maintaining correct combustion parameters and smooth operation of the OM640 unit,
• protecting against overheating and preventing the system from warming up too slowly.

Selecting a thermostat dedicated to a specific Mercedes engine family allows you to maintain factory cooling characteristics and avoid issues with the engine running too cold or overheating.

Compatibility with the OM640 Diesel engine

The presented thermostat is designed for use in Diesel OM640 engines, used in Mercedes W169 and W245 models. This ensures compatibility with the factory cooling system, housing geometry, and the thermostatic valve opening characteristics specified by the manufacturer.

Proper fitment for a specific engine unit means:

• correct positioning of the ports relative to the cooling hoses,
• compatibility with factory sensors and associated components,
• no need for modifications to the cooling system installation.

Performance characteristics and installation

As a component from the Thermostats and housings category, the product is designed to operate under demanding thermal and pressure conditions typical for diesel engines. It allows for the restoration of proper coolant circulation in the event of symptoms such as the engine warming up too slowly, fluctuations in operating temperature, or overheating under load.

When replacing the thermostat in a Mercedes W169 or W245, it is recommended to:

• check the condition of the cooling system hoses and clamps,
• replace or top up the coolant according to the manufacturer's recommendations,
• bleed the system after installation to avoid localized overheating.

Benefits of using a dedicated thermostat

Using a thermostat matched to the OM640 engine in a Mercedes W169/W245 allows you to maintain the engine's operating parameters at a level close to factory specifications. This translates into:

• more predictable behavior of the Diesel engine under various load conditions,
• stable operation of the vehicle's interior heating system,
• reduced risk of damage resulting from incorrect operating temperature.

This solution is particularly recommended when diagnosing temperature-related issues in compact Mercedes models, where the cooling system operates in the limited space of the engine bay.

Product condition and service application

The offered thermostat is a used component, making it an attractive option for economical cooling system repairs in older Mercedes W169 and W245 vehicles. It can be used both for the immediate replacement of a damaged part and for broader service work involving the cooling system in a diesel engine.

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 thermostat housings, connectors, or additional cooling system parts, check the available parts in the Mercedes Thermostats and housings category.

For drivers interested in a broader perspective on the differences between standard and performance components, an interesting addition to your knowledge might be the article about BMW M and M Performance components – you can find more information in the material BMW M Performance: how do BMW M components differ from standard ones?.