my BMW 5 Series F10/F11 (2010-2017) has a rough idle when cold what should I check

Solution

1. Preparation

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

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, torque wrench, anti-seize compound.
• Remove the ignition coils by unscrewing them and pulling them out carefully.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear or carbon buildup; replace if necessary.
• Install new spark plugs, applying anti-seize compound to the threads, and torque to manufacturer specifications (typically around 20 Nm).

3. Test and Replace Ignition Coils (if necessary)

• Reinstall ignition coils and check for proper electrical connection.
• If codes indicate faulty ignition coils, replace them as follows:
  • Disconnect the electrical connector from the coil.
  • Remove the coil retaining bolt and pull the coil out.
  • Install the new ignition coil and reconnect the electrical connector.

4. Inspect and Clean Mass Air Flow Sensor

• Tools Required: MAF sensor cleaner or isopropyl alcohol.
• Locate the MAF sensor in the air intake duct.
• Disconnect the MAF sensor connector, then unscrew the sensor from its housing.
• Clean the sensor gently with the MAF cleaner and reinstall it.

5. Check and Replace Coolant Temperature Sensor (if faulty)

• Tools Required: Wrench set, new coolant temperature sensor.
• Locate the coolant temperature sensor on the engine block or thermostat housing.
• Disconnect the electrical connector and unscrew the sensor.
• Install the new coolant temperature sensor and reconnect the connector.