my Volkswagen Golf MK7 (2015-2019) temperature gauge is fluctuating

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool completely before proceeding.

2. Replace Coolant Temperature Sensor

• Locate the coolant temperature sensor, typically near the thermostat housing.
• Disconnect the electrical connector from the sensor.
• Use a socket wrench to remove the sensor from the engine block.
• Install the new coolant temperature sensor and torque to manufacturer specifications (usually around 15 Nm).
• Reconnect the electrical connector.

3. Inspect and Replace Thermostat (if necessary)

• Drain the coolant from the system using a drain pan.
• Remove the thermostat housing bolts and take off the housing.
• Remove the old thermostat and inspect for proper operation; replace if faulty.
• Install the new thermostat, ensuring the correct orientation, and replace the housing. Torque bolts to specifications (around 10 Nm).
• Refill the cooling system with the appropriate coolant mixture.

4. Check Radiator Fan Operation

• Reconnect the battery and start the engine.
• Allow the engine to reach operating temperature while monitoring the radiator fan.
• If the fan does not activate, check the fan relay and wiring; replace components as necessary.