Replacing Audi Fuel Cap: Step-By-Step Guide For Beginners

Replacing the fuel cap in an Audi can be a simple task, but it depends on the model of the car and the type of replacement required. Some Audi models have electronically controlled gas doors, which can sometimes jam. In these cases, you may need to manually open the door before replacing it. The process for replacing a fuel door typically involves locating the rear access port, loosening the taillight mount, opening the gas door, removing the old lid, and installing a new one. Additionally, the fuel cap strap, which prevents the cap from falling, may need to be replaced if it breaks. This can be done by purchasing a new strap or using alternative solutions such as elastic bands or cords.

Removing the fuel filler flap solenoid

To remove the fuel filler flap solenoid, you will need to first drill holes in the four spots shown in the image using a 1/8" drill bit. Run the drill along the little rubber rectangles indicated in the image. Ensure that the drill does not go in any deeper than 1/4". You can use a drill stop to ensure this. Once the drilling is done and you've cleaned all debris, take out the gas cap. Now, start wiggling the black "Hinge Assembly" from side to side. Push one end in while pulling the other end out, then switch, until the whole assembly including the painted lid pops out. Put the gas cap back on to avoid fuel vapors from causing an unsafe work environment.

Next, take out the foam piece and set it aside. Unscrew the actuator by removing the two Phillips-head screws holding it onto the hinge assembly. Unplug the connector from the actuator.

Now, open the shelf panel in the passenger side of the trunk using the directions in your manual. Once you have removed it, you should see a red cable hanging freely or latched to something. If it is latched, you will need to unlatch it so you can remove the actuator and replace it with the new one.

From this point, everything just goes back into the car in reverse order. Insert the new actuator's emergency release cable from the gas lid side into the trunk. Latch the cable to wherever it was originally latched. Screw the new actuator to the hinge assembly. Plug in the electrical connector to the actuator. Put the foam piece back in. Take out the gas cap. Put the hinge assembly back in, it will need to be inserted at an angle to make it fit. Put the gas cap back on.

Opening the access port

To open the access port, first, open the trunk of your Audi A3 and locate the access port near the passenger side wheel well. It will look like a small circular cover recessed into the side of the trunk. Grab a flathead screwdriver and pry the cover upwards to open the access port.

Next, use a flathead screwdriver to loosen the top taillight mounting bolt and remove it. Although some consider this step optional, removing the bolt allows you to easily access the pull lever. Then, grab and pull the red cable.

Pulling the red cable will release the lock on the gas door. Now you can access the T20 bolt holding the entire assembly to the car. Loosen and remove the T20 Torx bolt and then pry the fuel lid cover up with your hands, working around the fuel cap ring, and pull it off. Finally, unhook the release cable.

Loosen the taillight mount

Now, you can access the T20 Torx bolt holding the entire assembly to the car. Loosen and remove this bolt, and then pry the fuel lid cover up with your hands, working around the fuel cap ring. Eventually, it will come off.

At this point, you can unhook the release cable. You have now successfully loosened the taillight mount and can move on to installing the new fuel lid.

Opening the gas door

To open the gas door manually, follow these steps:

• Open the trunk and locate the access port near the passenger-side wheel well. It will look like a small circular cover recessed into the side of the trunk. Use a flathead screwdriver to pry it upwards.
• Loosen the taillight mount using a flathead screwdriver. Although some consider this step optional, removing the bolt allows you to easily access the pull lever.
• Grab and pull the red cable. Pulling the cable will release the lock on the door and allow you to access the T20 bolt holding the entire assembly to the car.
• Loosen and remove the T20 Torx bolt and remove the gas cap.
• Pry the fuel lid cover up with your hands, working around the fuel cap ring, and eventually pull it off. Now, unhook the release cable.

Once you have manually opened the gas door, you can proceed to replace the fuel cap.

Installing the new lid

Now that you have removed the old fuel cap, it is time to install the new one. Here is a step-by-step guide on how to do it:

• Connect the release wire: Start by connecting the release wire to the new fuel cap lid. This wire is important as it allows you to open the fuel cap when needed.
• Install the lid and the fuel door: Place the new lid into the opening, ensuring it is securely attached. Then, install the fuel door, which is the small flap that covers the fuel cap.
• Install the gas cap: Place the gas cap back into the fuel door. This is the cap that you twist to open and close the fuel tank.
• Tighten the T20 Torx bolt: Using a T20 Torx screwdriver, tighten the bolt that holds the fuel cap and door in place. This will ensure that the assembly is securely attached to the car.
• Install the taillight mounting bolt: Use your flathead screwdriver to tighten the top taillight mounting bolt. This step is optional but can provide easier access to the fuel cap area.
• Place the cable release back inside: Put the cable release back into its original position inside the trunk. This cable is connected to the fuel door release mechanism.
• Cover the rear access: Finally, cover the rear access port that you opened earlier. This is usually a small circular cover located near the passenger-side wheel well in the trunk.

Make sure to paint the new fuel lid to match the colour of your Audi. Alternatively, you can purchase a pre-painted lid that matches your car's colour.

Frequently asked questions