Thermostat Housing: Service and Repair

Coolant Thermostat Housing

Special tools, testers and auxiliary items required

• Hose Clamp Pliers (V.A.G 1921)

• Drip Tray for Workshop Crane (VAS 6208)

Removing

• Drained coolant must be stored in a clean container for disposal or reuse.


Risk of scalding due to hot steam and hot coolant.

• When the engine is warm the cooling system is under pressure.

• Reduce pressure by covering coolant reservoir cap with a cloth and carefully opening.

- Open cap of coolant expansion tank.

- Remove center noise insulation fasteners - 1 to 3 -.





- Place (VAS 6208) under engine.

Vehicles with drain plug:

- Turn drain plug - arrow - on radiator left, place assisting hose on supports if necessary.





Vehicles without drain plug:

- Remove lower coolant hose - 2 - from radiator by removing retaining clamps.

All Vehicles

- Disconnect electrical connector - 1 - at engine coolant temperature (ECT) sensor (on radiator) (G83).

- Also remove lower coolant hose to after-run coolant pump (V51) - arrow - and allow remaining coolant to drain.





• Shown in illustration on vehicle with Direct Shift Gearbox transmission.


Observe safety precautions when disconnecting the battery.

- Remove tool formed insert under luggage compartment floor covering.

- Remove cover - arrow - for battery compartment





- Remove formed insert from over the battery.

- With ignition switched off, disconnect Battery Ground (GND) cable - arrow -.





- If equipped, remove vacuum hose - 2 - to air guide hose.





- Disconnect air guide hose - 1 - at throttle valve control module (J338).

- Disconnect mass air flow (MAF) sensor (G70) electrical connector - 3 -.

- Remove upper section of air filter housing - arrows -.

- Remove filter element.

- Pull off air guide cover - 1 -, disengage clips sideways to do so.





- Unclip air duct - 2 -.

- Remove lower section of air filter housing - arrows -.





- Remove vacuum line - arrow - at variable intake manifold actuator.





- Remove bolts - 1 - and - 2 - and remove vacuum actuator from intake manifold.

- Disconnect electrical connector - arrow - at engine coolant temperature (ECT) sensor (G62).





- Disconnect secondary air hose at position indicated by - arrow -.





- Free up air hose at bracket.

- Disconnect coolant hoses at positions indicated by - arrows -.





- Remove the bolts - arrows -.





- Pull transmission oil cooler coolant pipe bracket toward left.

- Swing Secondary Air Injection (AIR) system hose bracket forward.

- Remove bolt - arrow - at wiring harness bracket.






Press coolant pipe in direction of coolant pump using pry bar when removing coolant thermostat housing so that is not pulled off.

- Remove coolant thermostat housing - 2 - while pressing coolant pipe - 1 - toward coolant pump with pry bar.





Installing

Installation is in reverse order of removal, note the following:

• Replace seals.

- Fill with coolant => [ Filling ] Procedures.

- Connect battery. Required procedures.

Tightening Specifications