Audi A4 B9 A5 F5 2.0 TDI Ad Blue Tank Reservoir 8W0131878BN

Audi A4 B9 A5 F5 2.0 TDI Ad Blue Tank Reservoir is an original exhaust emission reduction system component designed for diesel engines. This part from the Fuel tanks and filler pipes group ensures stable storage of the AdBlue solution and its safe delivery to the exhaust system, supporting the proper operation of the SCR system. The blue finish makes it easy to identify the component in the assembly and service compartment.

Specifications and technical data

• SKU: 8W0131878BN
• Mark: Audi
• Condition: Used
• OEM Part Number: 8W0131878BN
• Substitutable numbers: 8W0131878BN, 8W0 131 878 BN, 8W0131969K, 8W0 131 969 K
• Fuel type: Diesel
• Color: Blue
• Category: Fuel Tanks & Filler Necks

Purpose and function in the AdBlue system

The AdBlue tank in an Audi with a 2.0 TDI engine is responsible for safe storage of the urea solution and its stable availability for the pump and dosing module. A properly functioning tank minimizes the risk of air locks, contamination, and errors in the nitrogen oxide reduction system, which translates into maintaining emission standards and the correct operation of the engine control unit.

This element is particularly important in vehicles operated on long routes, where the SCR system works continuously. The stable design of the tank supports even delivery of the medium to the exhaust system, which reduces the risk of the engine entering limp mode.

Construction, color, and service aspects

The AdBlue tank in this version features a characteristic blue color, which facilitates its identification during inspections and repairs. The blue marking is consistent with the automotive industry standard for components related to the AdBlue solution, reducing the risk of service errors.

As an element from the Fuel tanks and filler pipes group, the tank is designed for resistance to the urea solution and variable temperature conditions. The construction is designed to work with the factory mounting system and the original vehicle installation, which facilitates assembly and subsequent service.

Condition, fitment, and application in Audi

The offered tank is an Audi brand component, which means compliance with factory manufacturing and fitment standards. This makes it possible to maintain the original geometry of the AdBlue system and the correct positioning of nozzles and connections relative to the vehicle's installation.

The used condition allows for an economical replacement of a damaged or leaking tank while maintaining the proper functionality of the system. In the event of AdBlue system error messages, the problem often stems from leaks, mechanical damage, or internal tank issues, which is why its replacement is one of the basic diagnostic and repair steps.

Benefits of replacing the AdBlue tank

• Stable operation of the SCR exhaust emission reduction system in a diesel engine.
• Reduced risk of the engine entering limp mode due to AdBlue errors.
• Better repeatability of solution dosing and correct cooperation with vehicle electronics.
• Restoration of factory exhaust system parameters in the Audi A4 B9 / A5 F5 2.0 TDI.

By using an original component, you can maintain the consistency of the entire fuel and emission system, which is important for both component durability and subsequent computer diagnostics.

Technical support and component selection

When selecting an AdBlue tank, it is worth verifying compatibility by OEM number and vehicle data to ensure full compatibility with the mounting system and installation. In the case of extensive repairs to the fuel supply and emission reduction system, a guide describing the relationships between the tank, pump, and solution injection will be helpful – a detailed discussion can be found in the article Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration.

If you are planning a comprehensive repair or upgrade of the fuel supply and fluid storage area in your Audi and need other elements from the same group, such as additional tanks, supply lines, or filler pipes, check the available parts in the Audi fuel tanks and filler pipes category.