my BMW X3 F25 (2011-2018) has a hard time starting in cold weather

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, fuel pressure gauge, torque wrench.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Battery Replacement (if necessary)

1. Remove the battery cover (if applicable) using a socket set.
2. Disconnect the positive terminal first, followed by the negative terminal.
3. Remove the securing brackets and take out the old battery.
4. Install the new battery in the reverse order of removal. Torque the terminals to the manufacturer's specifications (usually around 10-15 Nm).
5. Reconnect the negative terminal first, followed by the positive terminal.

3. Starter Motor Inspection/Replacement (if necessary)

1. Remove the starter motor from the vehicle:
   • Disconnect the electrical connections from the starter solenoid.
   • Unbolt the starter motor from the transmission using a socket set.
2. Inspect the starter for wear or damage; if faulty, replace with a new unit.
3. Install the new starter motor, ensuring it is securely bolted and all electrical connections are properly reattached.

4. Fuel System Check (if necessary)

1. Connect the fuel pressure gauge to the fuel rail.
2. Turn the ignition to the "ON" position without starting the engine to check fuel pressure. It should be within the manufacturer's specified range (usually around 50-60 psi).
3. If pressure is insufficient, check the fuel pump and filter for blockages or failure. Replace as needed.