why does my BMW X3 F25 (2011-2018) coolant warning light keep coming on

Solution

1. Preparation

• Tools Required: Cooling system pressure tester, OBD-II scanner, basic hand tools, funnel, coolant.
• Ensure the engine is cool before beginning any work. Disconnect the battery for safety.

2. Address Coolant Leaks

• Sub-steps:
  1. Locate and assess the source of the leak identified during the diagnostic step.
  2. Replace any damaged hoses or components (e.g., radiator, water pump).
  3. If a leak is found in the radiator, consider whether it can be repaired or if replacement is necessary.

3. Replace Thermostat (if faulty)

• Sub-steps:
  1. Drain the coolant into a clean container.
  2. Remove the thermostat housing by unscrewing the bolts.
  3. Replace the old thermostat with a new one, ensuring the correct orientation.
  4. Reassemble the housing and tighten the bolts to the manufacturer’s specified torque.
  5. Refill the cooling system with the appropriate coolant mixture.

4. Test Water Pump (if needed)

• Sub-steps:
  1. If the water pump is suspected to be faulty, remove the drive belt to access it.
  2. Inspect for any signs of wear or leaks.
  3. Replace the water pump if it shows any signs of failure.
  4. Reinstall the drive belt and ensure proper tension.

5. Refill and Bleed Coolant System

• Sub-steps:
  1. Using a funnel, refill the cooling system with the appropriate coolant mixture.
  2. Start the engine and let it reach operating temperature, allowing air to escape.
  3. Keep an eye on the temperature gauge and add coolant as necessary until the system is bled of air.