how to fix P0300 code on BMW 5 Series G30/G31 (2017-2024)

Safety Warnings

• ⚠Safety Warnings:** Disconnect the battery before starting work on electrical components.
• ⚠Remove the engine cover (if applicable).
• ⚠Disconnect the electrical connectors from the ignition coils.
• ⚠Use a socket to remove the ignition coils and then the spark plugs.
• ⚠Install new spark plugs, ensuring they are gapped correctly according to manufacturer's specifications (usually 0.028 inches).
• ⚠Reinstall ignition coils and reconnect electrical connectors, then replace the engine cover.
• ⚠If damaged ignition coils were found, remove them as described above.
• ⚠Inspect for cracks or corrosion.
• ⚠Replace with new ignition coils, ensuring they are seated correctly.
• ⚠Reconnect electrical connectors.
• ⚠Remove injectors from the fuel rail.
• ⚠Use a fuel injector cleaning kit to clean the injectors or replace them if clogged.
• ⚠Ensure O-rings are replaced to prevent leaks during reinstallation.
• ⚠Connect the fuel pressure gauge to the fuel rail.
• ⚠Turn the ignition to the 'ON' position without starting the engine to check for pressure readings.
• ⚠Compare the readings to the manufacturer's specifications (usually between 50-60 psi). If low, inspect the fuel pump, filter, and lines for issues.
• ⚠Use a vacuum gauge to check the intake manifold vacuum.
• ⚠If low, inspect all vacuum hoses and the intake manifold for leaks. Repair or replace as necessary.
• ⚠Remove spark plugs and connect the compression tester to each cylinder.
• ⚠Crank the engine and record the compression readings.
• ⚠Compare readings to specifications (usually 130-180 psi). If any cylinder is significantly lower, investigate further for internal engine issues.
• ⚠Clear the error codes using the OBD-II scanner and take the vehicle for a test drive.
• ⚠Monitor the engine performance for any signs of misfire.
• ⚠Recheck for fault codes after the test drive to ensure P0300 does not reappear.
• ⚠Inspect for any exhaust smoke or unusual engine sounds.
• ⚠Regularly replace spark plugs and ignition coils as per the maintenance schedule.
• ⚠Use high-quality fuel and maintain clean fuel injectors.
• ⚠Monitor and maintain proper vacuum hose integrity.
• ⚠Address any engine performance issues promptly to avoid further damage.