how to fix a stuck thermostat in my Volkswagen Passat B8 (2015-2022)

Solution

1. Preparation

• Gather all tools and parts required before starting the repair.
• Ensure the engine is cool and disconnect the negative battery terminal to prevent any electrical issues.
• Tools Required: Socket set, screwdriver set, coolant catch pan, torque wrench.

2. Drain Coolant

• Place a coolant catch pan under the radiator.
• Open the radiator drain valve and allow the coolant to drain completely from the system.
• Once drained, close the drain valve.

3. Remove Thermostat

• Locate the thermostat housing, typically at the engine end of the upper radiator hose.
• Remove the bolts securing the thermostat housing using the socket set.
• Carefully lift the housing and remove the old thermostat. Note the orientation of the thermostat for proper installation.

4. Install New Thermostat

• Clean the mating surfaces of the thermostat housing and engine block to remove old gasket material.
• Position the new thermostat in the housing, ensuring it is oriented correctly.
• Apply a new gasket or sealant as required, and reattach the thermostat housing using the bolts. Torque them to the manufacturer's specifications (typically around 10-15 Nm).

5. Refill Coolant

• Refill the cooling system with the recommended type and mixture of coolant.
• Start the engine and allow it to reach operating temperature, monitoring the coolant level and topping off as necessary.

6. Reconnect Battery

• Reconnect the negative battery terminal.
• Ensure all tools are removed from the engine bay before closing the hood.