how to fix my BMW 5 Series G30/G31 (2017-2024) random misfire issues?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down before starting work.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if applicable.
• Disconnect ignition coil connectors.
• Use the spark plug socket to remove old spark plugs.
• Inspect the spark plug gap; ensure it matches manufacturer specifications (typically around 0.030 inches).
• Install new spark plugs, tightening them to the manufacturer’s torque specification (usually around 18-22 ft-lbs).
• Reconnect ignition coils and the engine cover.

3. Test and Replace Ignition Coils (if necessary)

• Tools Required: Multimeter, socket set.
• Use the multimeter to check the resistance of the ignition coils.
• If any coils are outside the specified range (consult the service manual), remove them using the socket set and replace with new units.
• Reinstall the ignition coils and reconnect connectors.

4. Clean or Replace Fuel Injectors

• Tools Required: Fuel injector cleaner, fuel injector removal tool.
• If injectors are clogged, consider using a fuel injector cleaning solution or removing them for a more thorough cleaning.
• If replacement is necessary, disconnect the fuel lines and electrical connectors, remove the old injectors, and install the new ones.
• Ensure that all seals are properly fitted to avoid leaks.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carb cleaner.
• Inspect hoses and gaskets for any visible wear or damage.
• Use a smoke machine to detect leaks in the intake system or spray carb cleaner around joints while the engine is running to check for changes in idle.
• Replace any damaged hoses or gaskets.