my BMW 5 Series F10/F11 (2010-2017) has a check engine light and code P0302, how to fix?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Tools Required: OBD-II scanner, socket set, torque wrench, spark plug socket, multimeter, compression tester, fuel injector cleaning kit.
• Safety Warnings: Disconnect the battery before working on electrical systems.

2. Replace Spark Plug

1. Remove the engine cover to access the ignition coils.
2. Disconnect the ignition coil connector for cylinder 2.
3. Remove the ignition coil using a socket set.
4. Use a spark plug socket to remove the old spark plug from cylinder 2.
5. Inspect the new spark plug for proper gap (typically 0.032-0.036 inches for BMW).
6. Install the new spark plug and torque it to the manufacturer’s specifications (usually around 23 lb-ft).
7. Reinstall the ignition coil and reconnect the connector.

3. Check/Replace Ignition Coil

1. If the spark plug replacement did not resolve the issue, test the ignition coil using a multimeter to check for proper resistance.
2. If the ignition coil is faulty, replace it with a new one.
3. Reinstall and reconnect the ignition coil.

4. Inspect/Replace Fuel Injector

1. If the ignition coil is functioning correctly, remove the fuel injector for cylinder 2.
2. Clean the injector using a fuel injector cleaning kit or replace it if clogged or defective.
3. Reinstall the fuel injector and ensure it is properly connected.

5. Perform Compression Test

1. If misfire persists, perform a compression test on cylinder 2.
2. If compression is low, further investigation may be needed for internal engine issues (e.g., valve leaks, piston rings).