This bulletin applies to 2019 BMW 430i Gran Coupe vehicles. While driving slowly with low engine rpm or while idling, a faint knocking or fluttering noise can be heard from inside the fuel tank. The customer may describe this noise as a “helicopter” noise from the rear of the vehicle.
Pressure fluctuations from the tank ventilation valve will cause the fuel tank filler pipe non-return valve to vibrate. In some cases this can be heard from inside the vehicle.
1. Duplicate the customer concern. Release the fuel filler cap while the noise is occurring (engine running). If the noise is eliminated by removing the fuel cap, go to Step 2. If not, go to step 3.
2. Reprogram the vehicle with ISTA 4.17.1X or higher. The target integration level will be F020-19-03-540 or higher.
Always connect a BMW-approved battery charger/power supply.
3. If the noise complaint continues with the fuel cap removed, the noise may be related to the fuel pump itself. Continue troubleshooting to isolate the root cause and repair as necessary.