Replacing a faulty fuel pump in your BMW E90 can seem daunting, but with the right tools and guidance, it’s a manageable DIY project. This guide provides a step-by-step walkthrough of the E90 Fuel Pump replacement process, helping you save on labor costs and get your car back on the road.
Accessing the Fuel Pump
The E90 fuel pump is located beneath the rear seat, inside the fuel tank. To access it, you’ll need to:
- Remove the rear seat: The rear seat bottom cushion typically pops up with a firm pull upwards.
- Remove sound deadening material: Pull back the sound insulation to expose the access panels.
- Remove access panels: Two access panels, secured by 10mm bolts, cover the fuel pump. Unbolt and remove these panels, disconnecting any electrical connectors before setting them aside.
- Remove lock rings: You’ll find lock rings securing the fuel lines to the pump. These can be stubborn. Penetrating oil and a mallet/screwdriver can help loosen them. Apply the penetrating oil, let it sit, then use the mallet and screwdriver to tap the lock ring in multiple spots until it loosens.
Disconnecting and Removing the Fuel Pump
Once the lock rings are off:
- Disconnect fuel lines: Unplug the fuel lines. Be prepared for some fuel leakage; it’s advisable to run the engine briefly with electrical connectors unplugged to reduce fuel pressure in the lines (exercise caution when doing this).
- Remove fuel pump: The fuel pump assembly should pull straight up. It may be helpful to grip it by one of the central connectors. Disconnect all hoses connected to the pump, including those running through the gas tank.
Installing the New E90 Fuel Pump
With the old pump removed:
- Replace the filter: If your new pump assembly includes a new fuel filter, install it now. Pay close attention to the orientation of the filter and any accompanying seals.
- Reconnect hoses: Carefully reconnect all hoses to the new fuel pump, ensuring they are properly seated and secured.
- Reinstall the pump: Position the new pump assembly into the tank and secure it.
- Reconnect fuel lines and lock rings: Reattach the fuel lines and secure them with the lock rings.
- Reassemble access panels and rear seat: Reinstall the access panels, reconnect electrical connectors, replace the sound deadening, and secure the rear seat.
Starting the Car After Replacement
After the installation:
- Initial start: The car may take a few attempts to start and might run rough initially. This is normal as the fuel system re-pressurizes.
- Check for leaks: With the engine running, inspect all connections for leaks.
- Address warning lights: If a warning light appears, diagnose and address the issue according to your vehicle’s service manual.
Replacing the E90 fuel pump is a challenging but achievable DIY task. This guide offers a detailed overview of the process. Always consult your vehicle’s service manual for specific instructions and torque specifications. Remember safety first! Work in a well-ventilated area and take necessary precautions when working with fuel.
