what causes my BMW 5 Series F10/F11 (2010-2017) engine to misfire

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, multimeter, fuel pressure gauge, torque wrench, compression tester.
• Ensure the vehicle is parked on a level surface, and the engine is cool.

2. Replace Spark Plugs

• Remove Engine Cover: Unscrew the bolts and gently lift off the cover.
• Disconnect Ignition Coils: Unplug the electrical connectors from each ignition coil.
• Remove Ignition Coils: Unscrew and carefully pull each coil out.
• Remove Old Spark Plugs: Use a spark plug socket to unscrew and remove old spark plugs.
• Install New Spark Plugs: Apply anti-seize compound to the threads of the new spark plugs, torque to manufacturer specifications (generally 22 ft-lbs).
• Reinstall Ignition Coils: Place ignition coils back and secure them with screws, then reconnect the electrical connectors.

3. Replace Faulty Ignition Coils (if necessary)

• Identify Faulty Coils: Use a multimeter to test the resistance of each coil; replace any that are out of spec.
• Install New Coils: Follow the same steps as above for removing and installing the ignition coils.

4. Clean or Replace Fuel Injectors

• Remove Intake Manifold: Disconnect necessary hoses and sensors, then unbolt and remove the intake manifold to access fuel injectors.
• Inspect Fuel Injectors: If clogged, clean using a fuel injector cleaner or replace them as necessary.
• Reinstall Intake Manifold: Ensure all gaskets are in good condition, then reinstall and torque to manufacturer specifications.

5. Check for Vacuum Leaks

• Inspect Vacuum Lines: Visually check all vacuum hoses for cracks or disconnections. Replace any faulty hoses.
• Use Smoke Test: If available, perform a smoke test to identify hidden leaks.