How do you Replace a VW's Thermostat?

Answer 1

Replacing a VW's (Volkswagen) thermostat differs from most other vehicles because of the placement of the thermostat. On most vehicles, the thermostat is in the intake manifold, easily found on the top of the engine or on the water pump, located on the lower half of the engine. Volkswagen places its thermostats behind the alternator, inside the engine block. This makes changing the thermostat a bit more challenging.

1.

Step 1

Disconnect the negative battery cable from the battery terminal with an adjustable wrench.

2.

Step 2

Search for the idle pulley on the passenger side of the vehicle. Wedge a crowbar on the backside of the pulley and pull the crowbar forward to loosen tension on the serpentine belt. With tension released, pull the serpentine belt off the alternator.

3.

Step 3

Remove the wire connectors from the alternator. To do so, push on the locking tabs and pull the connectors out of the alternator.

4.

Step 4

Remove the mounting bolt that secures the alternator to the motor with a 14mm wrench and pull the alternator out of the engine bay.

5.

Step 5

Search for the thermostat housing on the engine block. Follow the radiator hose that extends upward from the bottom of the radiator and locate the end that connects to the engine. The metal tube the hose connects to is the thermostat housing.

6.

Step 6

Remove the thermostat housing from the engine block, using a 12mm socket, ratchet and extension bar. Lift the housing off the thermostat and push it and the hose downward, out of your way. Some fluid may drain from the hose. Some drainage is normal.

7.

Step 7

Lift the rubber O-ring off the base of the engine block and discard it. Pull the old thermostat out of the engine block with your fingers.

8.

Step 8

Place the new thermostat into the engine block with the metal pin facing out of the engine. Lay a new rubber O-ring onto the engine block. Both balance in place.

9.

Step 9

Place the thermostat housing on top of the O-ring and secure it into place.

10.

Step 10

Mount the alternator back into place.

11.

Step 11

Pull the idle pulley upward with the crowbar and slide the serpentine belt over the belt pulley on the alternator.

12.

Step 12

Reconnect the negative battery cable.