how to fix P0300 code in BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, torque wrench
• Remove the engine cover if necessary.
• Use a socket to remove the spark plugs.
• Inspect each spark plug for wear; replace any that are worn or fouled.
• Install new spark plugs with a torque specification of 18 Nm (13 lb-ft).

3. Check and Replace Ignition Coils

• Tools Required: Socket set, flathead screwdriver
• Remove the electrical connectors from each ignition coil.
• Use a socket to remove the bolts securing the ignition coils.
• Replace any faulty ignition coils with new ones.
• Reattach the electrical connectors.

4. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner, syringe, or fuel injector cleaning kit
• Remove the fuel rail following the manufacturer’s service manual.
• Pull out the fuel injectors from the rail.
• Use a fuel injector cleaning solution to clean the injectors manually or use a cleaning kit.
• Reinstall the injectors into the rail and secure everything back in place.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner
• Visually inspect all vacuum lines for cracks or disconnections.
• Use a smoke machine to check for leaks or spray carburetor cleaner around suspected areas to identify leaks by observing engine RPM changes.
• Repair or replace any compromised vacuum lines.

6. Perform a Compression Test

• Tools Required: Compression tester
• Remove all spark plugs for access.
• Insert the compression tester into the first cylinder and crank the engine.
• Record the compression reading; repeat for all cylinders.
• Ensure all cylinders are within manufacturer specifications (typically around 150-200 psi).