why is my Volkswagen Passat B8 (2015-2022) engine overheating during summer

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and allow the engine to cool completely.
• Disconnect the negative battery terminal to ensure safety.

2. Coolant Check and Replacement

• Tools Required: Coolant funnel, drain pan.
• Remove the radiator cap and check the coolant level in the radiator.
• If low, add a 50/50 mix of approved coolant and distilled water.
• If the coolant is contaminated, drain the entire cooling system.
  • Attach a drain pan under the radiator.
  • Open the radiator drain plug and allow the coolant to fully drain.
• Close the drain plug and refill the system with fresh coolant.

3. Thermostat Inspection and Replacement

• Tools Required: Socket set, torque wrench, replacement thermostat.
• Remove the engine cover/hoses obstructing access to the thermostat housing.
• Disconnect the thermostat housing by removing the bolts (consult the torque specification for reinstallation).
• Remove the old thermostat and examine for proper operation; replace if faulty.
• Install the new thermostat and reassemble the housing, ensuring proper torque.

4. Radiator Fan Operation Check and Replacement

• Tools Required: Multimeter, socket set.
• Start the engine and allow it to reach operating temperature. Monitor the radiator fan.
• If the fan does not engage, check the relay and fuse for continuity.
• If the fan is defective, remove it by unscrewing the mounting bolts and disconnecting the electrical connector.
• Install the new radiator fan and secure it in place.

5. Final Checks

• Reconnect the battery terminal.
• Start the engine and allow it to idle while monitoring the temperature gauge.
• Check for leaks and ensure the cooling system is functioning properly.