why is my BMW 5 Series F10/F11 (2010-2017) engine running rough at idle

Solution

1. Preparation

• Gather tools and parts necessary for repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket set to remove the spark plug wires or coils.
• Unscrew the spark plugs using a spark plug socket.
• Inspect for wear, carbon build-up, or damage; replace with OEM specifications (torque to manufacturer's specs).
• Reinstall spark plugs, ensuring proper gapping as per specifications.

3. Check and Repair Vacuum Leaks

• Visually inspect all vacuum hoses and connections for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to identify leaks by spraying around suspected areas and observing for RPM changes.
• Replace any damaged hoses or gaskets as necessary.

4. Test and Replace Fuel Pressure Regulator

• Connect a fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure against specifications.
• If pressure is below specifications, replace the fuel filter and fuel pump if necessary.

5. Clean or Replace MAF Sensor

• Disconnect the MAF sensor electrical connector.
• Remove the MAF sensor from the intake duct.
• Clean with MAF sensor cleaner; if heavily contaminated, replace it.
• Reinstall the sensor and reconnect the electrical connector.