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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool down before starting work.

2. Inspect Ignition Components

• Spark Plugs:

  • Remove the ignition coil cover using a socket set.
  • Extract the spark plugs using a spark plug socket.
  • Inspect for wear or damage; replace if necessary.

• Ignition Coils:

  • Visually inspect ignition coils for cracks or damage.
  • Replace any faulty coils with new OEM coils.

3. Check Fuel System

• Fuel Pressure Test:

  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position without starting the engine; check the pressure reading.
  • Compare with manufacturer specifications (typically around 50-60 psi for BMW).

• Fuel Injector Inspection:

  • Remove the fuel injectors from the rail.
  • Clean or replace any clogged injectors.

4. Inspect Air Intake and Vacuum System

• Air Filter:

  • Remove the air filter and inspect for dirt and blockages; replace if necessary.

• Vacuum Leaks:

  • Check all vacuum hoses for cracks or disconnections.
  • Repair or replace any damaged hoses.

5. Test Engine Compression

• Use a compression tester:
  • Remove spark plugs.
  • Insert the compression tester into each cylinder.
  • Crank the engine and record the compression readings; compare to manufacturer specifications.

6. Reassemble and Final Checks

• Reinstall spark plugs, ignition coils, and air intake components.
• Reconnect the negative battery terminal.
• Clear the trouble codes using the OBD-II scanner.