my BMW X5 F15 has a rough idle when cold what could cause this

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to ensure safety.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if necessary.
• Use a socket set to remove the spark plug wires or coils.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; replace with new ones if necessary.
• Torque new spark plugs to manufacturer's specifications (usually around 18-22 ft-lbs).
• Reinstall spark plug wires or coils.

3. Clean Throttle Body

• Remove the throttle body from the intake manifold (ensure the throttle position sensor is disconnected).
• Use throttle body cleaner and a clean cloth to remove carbon deposits.
• Reinstall the throttle body and reconnect sensors.

4. Check and Replace Fuel Filter (if applicable)

• Locate the fuel filter, which may be integrated with the fuel pump on some models.
• Release fuel pressure from the system.
• Disconnect the fuel lines from the filter and remove it.
• Install a new fuel filter, ensuring proper orientation and secure connections.

5. Inspect and Replace Engine Coolant Temperature Sensor

• Locate the coolant temperature sensor (usually near the thermostat).
• Disconnect the electrical connector.
• Remove the sensor using a socket or wrench.
• Install the new sensor and reconnect the electrical connector.