how to troubleshoot my Volkswagen Golf MK7 (2015-2019) when it overheats

Solution

1. Preparation

• Ensure the engine is cool before starting work on the cooling system.
• Gather tools and parts necessary for the repair.

2. Check and Refill Coolant

• Sub-steps:
  1. Open the coolant reservoir cap carefully to avoid any pressurized coolant.
  2. Inspect coolant level; if low, refill with the appropriate coolant mixture (G12 or G13 for VW).
  3. Replace the cap securely after refilling.

3. Replace Thermostat (if faulty)

• Tools Required: Socket set, Torque wrench, Gasket scraper
• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Drain the coolant from the system into a suitable container.
  3. Remove the thermostat housing by unscrewing the bolts.
  4. Take out the old thermostat and clean the mounting surface thoroughly.
  5. Install the new thermostat, ensuring the correct orientation.
  6. Reattach the thermostat housing and torque to specifications (typically 10-12 Nm).
  7. Refill the coolant system and bleed air from the system.

4. Repair or Replace Water Pump (if leaking or malfunctioning)

• Tools Required: Socket set, Pliers, Gasket scraper
• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Drain the coolant from the system.
  3. Remove any components obstructing access to the water pump (e.g., timing belt, pulleys).
  4. Unbolt the water pump and carefully remove it from the engine block.
  5. Clean the mounting surface and install the new water pump with a new gasket.
  6. Reassemble components in reverse order and refill the coolant.

5. Inspect and Repair Radiator Fan (if inoperative)

• Tools Required: Multimeter, Socket set
• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Disconnect the wiring harness from the radiator fan.
  3. Use a multimeter to test for voltage at the fan connector when the engine is hot.
  4. If no voltage is present, check the fuses and relays associated with the cooling system.
  5. If the fan is faulty, remove it by unbolting and replace it with a new unit.