Thermostat Housing: Service and Repair

Engine Coolant Thermostat Housing Replacement (V6)

Tools Required

EN-48536 - Frame Support Tool (Engine Lower 65 mm Kit)

For equivalent regional tools, refer to Special Tools Tools and Equipment.

Removal Procedure

Warning:
Refer to Battery Disconnect Warning Battery Disconnect Warning.


1. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection (Primary) Battery Negative Cable Disconnection and Connection (Primary)Battery Negative Cable Disconnection and Connection (Auxiliary) Battery Negative Cable Disconnection and Connection (Auxiliary).

2. Remove the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement (Lower Panel) Air Inlet Grille Panel Replacement (Lower Panel)Air Inlet Grille Panel Replacement (Upper Panel) Air Inlet Grille Panel Replacement (Upper Panel).

3. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement Air Cleaner Outlet Duct Replacement.

Warning:
Refer to Radiator Cap Removal Warning Service Precautions.


4. Ensure the engine temperature is below 50°C before removing the radiator cap.

5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle Service and Repair.

6. Drain the cooling system. Refer to Cooling System Draining and Filling Cooling System Draining and Filling.

Note:
Remove the lower intake manifold for LY7 equipped vehicles and Do Not separate the upper and lower intake manifolds.

7. Remove the intake manifold. Refer to Intake Manifold Replacement Service and Repair.

Note:
Ensure material used to cover cylinder head inlet ports is lint free to prevent any foreign matter entering the ports.

8. Cover the exposed cylinder head inlet ports.





9. Raise the securing lock (3) from the radiator support bracket (2) by 10 mm on both sides.

10. Remove the radiator support bracket (2) from the radiator slide pin assembly (1) on both sides.

11. Remove the front air deflector

12. Remove the engine splash shield if equipped.

13. Remove the engine coolant inlet pipe. Refer to Engine Coolant Inlet Pipe Replacement Engine Coolant Inlet Pipe Replacement.

14. Remove the exhaust system. Refer to Exhaust System Replacement (V6) Service and RepairExhaust System Replacement (V8) Service and Repair.

15. Remove the propeller shaft. Refer to Propeller Shaft Replacement (Except 4L60) Propeller Shaft Replacement (Except 4L60).

Note:
Right hand drive shown, left hand drive similar.





Note:
The front wheels of the vehicle must be maintained in the straight ahead position and the steering column must be in the LOCK position before disconnecting the steering column or intermediate shaft. If these procedures are not followed, incorrect alignment of some components during installation will result and damage to the SIR coil assembly will occur.

Note:
Observing the orientation of the intermediate steering shaft (1) with reference to the pinion shaft (3) will minimize the potential of incorrect steering column assembly alignment.

16. Mark the intermediate steering shaft (1) in relation to the pinion shaft (3).

Note:
Bolts with micro-encapsulated thread sealant must be discarded after removal.

17. Remove the intermediate shaft to pinion shaft retaining bolt (2).

Discard the bolt.

18. Disconnect the intermediate shaft (2) from the pinion shaft (3).

Note:
Step 20 to 35 detail how to use the engine and transmission 65 mm drop tool. If this procedure is known, go to Step 36.

19. Using special tool EN-48536 lower the engine and transmission assembly 65 mm.

Note:
The engine mounts must NOT bend or deflect from the vertical position, damage to the mount will occur.

20. Support the power train with a suitable jack or table.





21. Remove the transmission support to body retaining bolts (1).





22. Remove the front and rear sub frame to front chassis rail retaining bolts (1).





Note:
Do not tighten the bolts at this stage.

23. Replace the front and rear sub frame to body retaining bolts with four (M16 x 2.0) 160 mm bolts from special tool kit EN-48536.

24. Install the bolts until 2 mm of the thread remains visible below the sub frame.





Note:
Do not tighten the bolts at this stage.

25. Replace the transmission support to body retaining bolts with the two (M10 x 1.5) 115 mm bolts (2) from special tool kit EN-48536 adjacent to each other. e.g. Left hand front and Right hand rear.

26. Install the bolts until 65 mm of bolt remains visible (A) between the bolt heads (2) and the transmission mount (1).





27. Remove the centre sub frame to body retaining bolts (1).

28. Lower the powertrain slowly until the sub frame and transmission assembly is resting on the bolt heads.





29. Insert the 65 mm spacer blocks (1) between the sub frame (2) and chassis rails (3).

30. Tighten the front and rear sub frame retaining bolts to 95 Nm (70 lb ft).

31. Install the remaining two (M16 x 2.0) 115 mm centre sub frame to body retaining bolts from special tool kit EN-48536 to the front sub frame and tighten to 95 Nm (70 lb ft).





32. Position the engine support plate (1) to the front sub frame.

33. Install the four (M8 x 1.25) 28 mm engine support plate to front sub frame retaining bolts (2) from special tool kit EN-48536 and tighten to 10 Nm (89 lb in).

34. Support the transmission with a suitable jack or table.





35. Disengage the heater hose quick connect fitting retaining clip (3) with a suitable screwdriver.

36. Detach the heater hoses (1) from the heater pipes (2).





37. Remove the heater pipe assembly to cylinder head retaining bolt (3).

38. Remove the heater pipe assembly to engine coolant thermostat housing retaining bolts (5).

39. Remove the heater pipe assembly (4) from the cylinder head (2) and engine coolant thermostat housing (1).

40. Remove the heater pipe assembly to engine coolant thermostat housing O-ring seals (6).





Note:
The engine coolant thermostat housing has one longer bolt which is located in the upper left of the housing.

41. Remove engine coolant thermostat housing to cylinder head retaining bolts (4) and plastic retainers (3).

42. Remove engine coolant thermostat housing (2).

43. Discard the engine coolant thermostat housing gasket (1).

Installation Procedure





1. Assemble the engine coolant thermostat housing (2), with a NEW gasket (1), to the cylinder head with the retaining bolts (4) and retainers (3).

Caution:
Refer to Fastener Caution Fastener Caution.

2. Install engine coolant thermostat housing (2) to the cylinder head and tighten the engine coolant thermostat housing to cylinder head retaining bolts (4) to 10 Nm (89 lb in).





Note:
Ensuring new O-ring seals (6) are fitted to the heater pipe assembly (4).

3. Install the heater pipe assembly to engine coolant thermostat housing O-ring seals (6) to the heater pipe assembly (4).

4. Install the heater pipe assembly (4) to the cylinder head (2) and engine coolant thermostat housing (1).

5. Install the heater pipe assembly to engine coolant thermostat housing retaining bolts (5) and tighten to 9 Nm (80 lb in).

6. Install the heater pipe assembly to cylinder head retaining bolt (3) and tighten to 35 Nm (26 lb ft).





Caution:
Refer to Installing Hoses without Twists or Bends Caution Installing Hoses without Twists or Bends Caution.

Note:
Make sure the heater hose quick connect fitting retaining clip is securely engaged into the heater hose quick connect fitting (3).

7. Attach the heater hoses (1) to the heater pipes (2).

8. Install the engine coolant inlet pipe. Refer to Engine Coolant Inlet Pipe Replacement Engine Coolant Inlet Pipe Replacement.





Note:
Step 9 to 20 detail how to use the engine and transmission 65 mm drop tool. If this procedure is known, go to Step 21.

9. Remove the four (M8 x 1.25) 28 mm engine support plate to front sub frame retaining bolts (2).

10. Remove the engine support plate (1) from the front sub frame.





11. Loosen the six sub frame to front chassis rail retaining bolts (1 and 2) by one turn each.

12. Remove the 65 mm spacer blocks from between the sub frame and chassis rails.

13. Raise the power train slowly until the sub frame and transmission mount are lifted off the bolt heads and the power train is positioned back up into the engine bay.





14. Remove the centre (M16 x 2.0) 115 mm sub frame to front chassis rail retaining bolts (1).

15. Install the original centre sub frame to front chassis rail retaining bolts (1) and tighten to 160 Nm (118 lb ft).





16. Tighten the front sub frame to front chassis rail retaining bolts to 160 Nm (118 lb ft).





17. Tighten the rear sub frame to front chassis rail retaining bolts to 240 Nm (178 lb ft).





18. Remove the two (M10 x 1.5) 115 mm special tool kit EN-48536 transmission support to body retaining bolts (1).

19. Install the four original transmission support to lower sub frame retaining bolts (1) and tighten to 55 Nm (41 lb ft).

20. Remove the support from under the power train.

Note:
Right hand drive shown, left hand drive similar.





Note:
The intermediate steering shaft and pinion shaft splines must be installed in the position recorded during removal and aligned with the marks previously made.

21. Connect the intermediate steering shaft (1) to the pinion shaft (3).

22. Install a NEW intermediate steering shaft to pinion shaft retaining bolt (2) and tighten to 25 Nm (18 lb ft).





23. Install the radiator support bracket (2) to the radiator slide pin assembly (1) on both sides.

24. Push the securing lock (3) into the radiator support bracket (2) making sure it is correctly seated on both sides.

25. Install the propeller shaft. Refer to Propeller Shaft Replacement (Except 4L60) Propeller Shaft Replacement (Except 4L60).

26. Install the exhaust system. Refer to Exhaust System Replacement (V6) Service and RepairExhaust System Replacement (V8) Service and Repair.

27. Install the engine coolant inlet pipe. Refer to Engine Coolant Inlet Pipe Replacement Engine Coolant Inlet Pipe Replacement.

28. Install the engine splash shield if equipped.

29. Install the front air deflector.

30. Remove the material used to cover the exposed cylinder head inlet ports.

31. Lower the vehicle.

32. Install the intake manifold. Refer to Intake Manifold Replacement Service and Repair.

33. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement Air Cleaner Outlet Duct Replacement.

34. Install the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement (Lower Panel) Air Inlet Grille Panel Replacement (Lower Panel)Air Inlet Grille Panel Replacement (Upper Panel) Air Inlet Grille Panel Replacement (Upper Panel).

35. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection (Primary) Battery Negative Cable Disconnection and Connection (Primary)Battery Negative Cable Disconnection and Connection (Auxiliary) Battery Negative Cable Disconnection and Connection (Auxiliary).

36. Fill the cooling system. Refer to Cooling System Draining and Filling Cooling System Draining and Filling.

37. Inspect the cooling system for coolant leaks and repair as necessary.