A gas leak in a Volkswagen can show up practically anywhere on the vehicle. The gas tank is located perpendicular to the rear wheels and the gas line runs from the tank, down the driver’s side of the vehicle and into the engine bay. Although you have to search a large area for a gas leak, the process is not overly difficult. After a visual inspection, the next step requires only a large cardboard box.
Open the engine hood and prop it with the hood prop. Inspect the engine for gas leaks. The fuel rails are square tubes that are located beside the intake manifold. They have several electrical connectors going to them. The fuel line connects to the right side fuel rail and a jumper line connects to the left side fuel rail. If a fuel leak exists in the engine bay, it will be in the fuel rail.
Turn the Volkswagen on and inspect for any spraying fuel coming from the fuel rail, jumper line and fuel line inside of the engine bay. Use a flashlight to enhance visibility. The fuel line is pressured. With the engine on, the leak will spray a fine mist. If the leak is not detected in the engine bay, stop the engine and move to the next step.
Place cardboard under the engine, the gas tank and the driver’s side of the vehicle. Ensure the entire area is covered with cardboard to prevent overlooking the leak.
Start the engine and allow the Volkswagen to run for a few minutes. While it is running, inspect the cardboard for signs of moisture buildup. If a spot is detected, inspect the gas line directly above the wet area for leaks. If no spots are detected under the engine bay or on the driver’s side of the vehicle, move to the next step.
Allow the vehicle to sit on the cardboard for at least 24 hours. Often, if the leak is not in the pressurized gas line or fuel rail it is in the gas tank. Even with the engine on, there is no pressure in the gas tank so it may take time for the leak to show itself. Allowing time for moisture buildup on the cardboard will show where the leak is on the gas tank.
