Thermostat Housing: Service and Repair

Engine Coolant Thermostat Housing Replacement (LAF)

Removal Procedure




1. Drain the coolant from the engine block at the water pump drain. After the coolant has drained, tighten the drain bolt.
Note: A drain has been provided at the bottom of the water pump for engine block coolant drainage.

2. Lower the vehicle.




3. Disconnect the engine wiring harness electrical connector (1) from the engine coolant temperature (ECT) sensor.
4. Remove the heated oxygen sensor (HO2S) electrical connector rosebud clip from the thermostat housing.




5. Reposition the radiator outlet hose clamp (2) at the thermostat housing.
6. Remove the radiator outlet hose (4) from the thermostat housing.




7. Remove the exhaust heat shield studs (2).
8. Remove the exhaust heat shield.




9. Remove the HVAC heater inlet hose (2) from the thermostat housing.




10. Remove the HVAC heater outlet hose (2) from the thermostat housing.
11. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).




12. Remove the ECT sensor, if necessary.




13. Remove the thermostat housing bolts.

Note: Twist the water transfer pipe while pulling in order to remove it from the water pump.

14. Remove the thermostat from the vehicle.
15. Remove the water transfer pipe from the thermostat housing, if necessary.
16. Remove and discard the water transfer pipe O-ring seals, if necessary.




17. Remove the thermostat cover bolts and cover, if necessary.
18. Remove the thermostat, if necessary.
19. Remove and discard the thermostat cover O-ring seal, if necessary.
20. Remove all debris and thread sealant from the engine coolant temperature (ECT) sensor and bolt holes if the housing is being re-used.

Installation Procedure




1. Install a NEW thermostat cover O-ring seal into the recess groove.
2. Install the thermostat, if necessary.

Caution: Refer to Fastener Caution (Fastener Caution).

3. Install the thermostat cover bolts, if necessary and tighten to 10 Nm (89 lb in).
4. Install a NEW thermostat housing to engine gasket onto the thermostat housing.
5. Load the thermostat housing assembly into position.





Note: The water feed pipe seals can be lightly lubricated with coolant to aid during installation.

6. Install NEW O-ring seals onto the water feed pipe.

Note: Lubricate the O-rings with coolant ONLY.

7. Install the water feed pipe into the thermostat housing aligning locator tab.
8. Align the water pipe to water pump.
9. Seat the water feed O-ring seal by pushing inward toward the water pump. Take care not to tear or damage the O-ring.
10. Position the thermostat housing against the engine.
11. Install the thermostat housing bolts and tighten to 10 Nm (89 lb in).




12. If reinstalling the old sensor, coat the threads with sealant. Refer to Adhesives, Fluids, Lubricants, and Sealers (Adhesives, Fluids, Lubricants, and Sealers).
13. Install the ECT sensor, if necessary and tighten to 20 Nm (15 lb ft).
14. Lower the vehicle.




15. Install the HVAC heater inlet hose (2) to the thermostat housing.




16. Install the HVAC heater outlet hose to the thermostat housing.
17. Install the exhaust heat shield.Refer to Exhaust Manifold Heat Shield Replacement (LAF) (Service and Repair)




18. Install the radiator outlet hose to the thermostat housing.
19. Position the radiator outlet hose clamp at the thermostat housing.




20. Connect the engine wiring harness electrical connector (1) to the ECT sensor (1).
21. Install the HO2S electrical connector rosebud clip to the thermostat housing.




22. Verify the drain valves at the radiator and water pump are closed.
23. Lower the vehicle.
24. Fill the cooling system. Refer to Cooling System Draining and Filling (Static LF1 or LFW) (Cooling System Draining and Filling (Static))Cooling System Draining and Filling (GE 47716) (Cooling System Draining and Filling (GE 47716))Cooling System Draining and Filling (Static LAF) (Cooling System Draining and Filling (Static)).