Do you have any issues with your BMW, relating to the fuel system? One of the likely suspects is the fuel tank vent valve. This small, but very important, subassembly is designed to control the flow of vapors from the fuel tank into the engine. If it fails, you will experience low performance, rough running, or even the smell of fuel in the car. Here are the common symptoms of a faulty vent valve in your BMW’s fuel tank and how to address them to prevent a major repair on your BMW.
What is The Use of the Fuel Tank Vent Valve?
The fuel tank vent valve is a part of the evaporative emissions control system (EVAP) of your car. This system helps reduce the movement of fuel vapors from the tank to the engine, making your BMW more environmentally friendly. The valve also ensures that these vapors allowed into the engine are not expelled in the air. At its optimal function, the valve will open and close to manage the vapor flow. However, if the valve is blocked or jammed, it causes several issues.
Symptoms of a Faulty BMW Fuel Tank Vent Valve
- Strong Fuel Smell: If the valve is not functioning as a checkpoint of the fuel vapor, you might notice a gasoline smell inside your BMW or nearby, especially when parked.
- Check Engine Light On: Another indication that your fuel tank vent valve is defective is when the warning light is on. This light can come on for several reasons, but if there is a problem with the vent valve when you scan the EVAP system, it should come up with an error code that points to the problem.
- Difficulty Filling the Gas Tank: A blocked or faulty vent valve can cause problems filling up your gas tank. If you observe that the pump turns off every time you try to refuel, this may be a sign that the fuel vapors are not expelled sufficiently.
How to Identify a Failed Fuel Tank Vent Valve
- Check for Error Codes: Connect an OBD-II scanner to the vehicle and check for any error codes. If the fuel tank vent valve is bad, you will get codes like P0441 or P0455.
- Inspect the Valve: A physical inspection of the valve and its neighboring components, can reveal problems such as cracks or wear.
- Perform a Smoke Test: When diagnosing the EVAP system, mechanics commonly conduct a smoke test to identify leakages. This is done by introducing smoke into the system to ascertain if the vapors are escaping through the cracks and holes in the vent valve.
Solving a Failing Fuel Tank Vent Valve
- Replace the Valve: The simplest solution is to replace the bad vent valve. This process should be done by an experienced mechanic. The replacement valve must be fitted properly and carefully connected to the EVAP system to have it function properly.
- Check for Related Issues: When replacing the valve, it may also be a good time to inspect other parts of the EVAP system. Change any hoses that may be blocked or wiring that may be damaged to avoid malfunction of the system.
- Reset the Error Codes: Once a valve has been replaced, you should have other error codes related to the EVAP system cleared via an OBD-II scanner. This will help to turn off the check light.
Choose Motor Cars International For All Your BMW Repairs
When it comes to diagnosing and 
repairing BMW problems, Motor Cars International is the company you can turn to. Our expert mechanics can handle any challenge in your vehicle, including vent valve issues. We boast of fast and efficient services, to enable your car to get back on the road as soon as possible.
Our team of professional technicians will use the latest diagnostic equipment to scan and repair any faults detected. If you think that your BMW’s fuel tank vent valve is problematic, do not wait for the situation to worsen. You can come to our shop in Bridgewater, MA and our experts will help you fix the problem. We also assist people from all over Easton, Norton, Raynham, and Sharon, MA. Call us now to book an appointment.
* White BMW Car image credit goes to: Brandon Woyshnis.