Audi Q7 4L 4.2 TDI BTR Diesel Fuel Filler Cap Tank Lid Drip Tray Cover 4L0809857

Audi Q7 4L 4.2 TDI BTR Diesel Fuel Filler Cap Tank Lid Drip Tray Cover is an original body component from the Fuel filler flaps and caps group, designed for the diesel version. It ensures a tight seal of the filler neck, protecting the diesel fuel system from contaminants and unauthorized external access, while maintaining the factory body lines of the Audi.

Specifications and technical data

• SKU: 4L0809857
• Mark: Audi
• Condition: Used
• OEM Part Number: 4L0809857
• Substitutable numbers: 4L0809857, 4L0 809 857
• Fuel type: Diesel
• Category: Fuel Tank Caps

Purpose and technical function

The presented fuel filler cap with lid is designed specifically for the Diesel fuel system in the Audi Q7 4L generation model with the 4.2 TDI BTR engine. The component is responsible for the proper closing of the filler neck, stable guidance of the cap, and maintaining the appropriate operating conditions of the fuel system, which is important for both operational safety and the durability of fuel supply components.

Thanks to its factory geometry and correct mounting profile, the cap with lid works with the original socket in the body, minimizing the risk of leaks and problems with closing the flap during daily vehicle use.

Construction and fitment for Audi Q7 4L

The element combines the function of an external lid and an internal fuel filler cap, creating a cohesive assembly mounted in the side body area. The design is adapted to the characteristic lines of the Audi Q7 4L, which allows for maintaining a uniform vehicle appearance after replacing a damaged or worn component.

Properly shaped clips and guides allow for correct seating in the factory mounting points, without the need for bodywork modifications or interference with the original body structure. As a result, the replacement is predictable in terms of time and scope of work, and the final effect remains consistent with the manufacturer's specifications.

Condition, origin, and benefits of using a used part

The product comes from dismantling and is offered as a used part, which allows for an economical vehicle repair while maintaining the original Audi specification. Unlike aftermarket replacements with uncertain fitment, the OEM component ensures proper alignment with the bodywork and compatibility with the factory opening and closing mechanism.

Using an original, used lid with a cap is particularly beneficial in the case of post-accident repairs or body part replacements, where visual consistency, proper lock operation, and maintaining the tightness of the diesel fuel system are essential.

Operation in a diesel fuel system

In vehicles with a diesel engine, a properly functioning fuel filler cap is important for protection against moisture, dust, and other contaminants that could enter the tank. A tight seal also limits the risk of fuel vapor evaporation and helps maintain stable operating conditions for the fuel supply system.

If you want to better understand the relationships between the filler cap, tank, pumps, and injectors, and learn about good maintenance practices, it is worth checking out the guide on the fuel system: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration.

Expanding your Audi fuel filler upgrade

If you are planning a comprehensive repair or upgrade of the fuel filler area in your Audi and need other components from the same group, such as additional lids, mounts, or seals, check out the available parts in the Audi fuel filler flaps and caps category.