how to fix my BMW 5 Series G30/G31 (2017-2024) that keeps throwing P0300 code?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool down before working on any components.

2. Inspect and Replace Spark Plugs

• Remove engine cover if applicable.
• Use a socket wrench to remove each spark plug.
• Inspect spark plugs for wear, carbon buildup, or damage.
• Replace with OEM or high-quality aftermarket spark plugs, ensuring the gap is set to manufacturer specifications (usually around 0.032 - 0.035 inches).
• Torque plugs to the specified value (typically around 15 Nm).

3. Check and Replace Ignition Coils

• Carefully disconnect the wiring harness from each ignition coil.
• Remove the bolts securing the ignition coils using a socket set.
• Replace any faulty ignition coils with new ones, ensuring they are compatible with the G30/G31 model.
• Reconnect the wiring harness to each coil securely.

4. Inspect and Clean Fuel Injectors

• Remove the fuel rail if necessary, following the manufacturer's instructions.
• Use a fuel injector cleaning kit to clean the injectors or replace them if they are clogged or leaking.
• Reinstall the fuel rail and ensure all connections are secure.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses for cracks or damage.
• Use a smoke machine or carburetor cleaner to identify leaks while the engine is running.
• Replace any damaged hoses.

6. Perform Engine Compression Test

• Remove spark plugs and insert a compression gauge into each cylinder.
• Crank the engine and record the compression readings.
• Compare readings against manufacturer specifications (typically around 150-200 psi).
• Address any cylinders with low compression by checking for valve issues or head gasket leaks.