how to fix engine overheating issues in my BMW 3 Series G20/G21 (2019-2024)?

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the engine is cool before starting work to avoid burns.
• Disconnect the battery to prevent electrical shorts.

2. Replace the Thermostat (if faulty)

• Remove engine cover (if applicable) using a socket set.
• Disconnect the thermostat housing:
  • Remove any hoses attached to the thermostat housing.
  • Unbolt the thermostat housing from the engine.
• Replace the thermostat:
  • Remove the old thermostat and clean the mating surfaces.
  • Install the new thermostat in the housing.
• Reattach the thermostat housing and reconnect hoses.
• Torque the bolts to manufacturer specifications (check BMW service manual for specific values).

3. Inspect and Replace the Cooling System Components

• Inspect the water pump:
  • Remove the serpentine belt using a belt tensioner tool.
  • Check for any leaks or excessive play in the water pump pulley.
  • Replace the water pump if any issues are detected.
• Flush the cooling system:
  • Use a cooling system flush chemical as per manufacturer instructions.
  • Drain the old coolant and refill with a 50/50 mix of BMW-approved coolant.
• Check the radiator:
  • Inspect for blockages or damage; replace if necessary.

4. Verify Cooling Fan Operation

• Test the cooling fans:
  • Reconnect the battery.
  • Start the engine and let it idle until the temperature gauge rises.
  • Ensure the cooling fans activate at the specified temperature.