Important: This engine uses a sequential multiport fuel injection system. Injector wiring harness connectors must be connected to their appropriate fuel injector or exhaust emissions and engine performance may be seriously affected.

1. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
2. Remove the left and right valve rocker arm covers. Refer to Valve Rocker Arm Cover Replacement - Left Side and Valve Rocker Arm Cover Replacement - Right Side .
3. Remove the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement .
4. Reposition the radiator inlet hose clamp at the thermostat housing.
5. Remove the radiator inlet hose from the thermostat housing.



6. Disconnect the heater inlet hose (1) quick connect.



7. Remove the heater inlet pipe nut.
8. Remove the heater inlet pipe from the lower intake manifold.



9. Remove the lower intake manifold bolts.
10. Remove the lower intake manifold.
11. Remove the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .



12. Remove the lower intake manifold gaskets and seals.
13. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
14. Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
15. Remove all the loose room temperature vulcanizing (RTV) sealer (1).



16. If replacing the lower intake manifold perform the following steps, otherwise proceed to step 4 of the installation procedure.
17. Remove the thermostat housing bolts and housing.
18. Remove the thermostat.

Important: All gasket-mating surfaces need to be free of oil and foreign material. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number to clean the surfaces.

1. If the lower intake manifold was replaced perform the following steps, otherwise proceed to step 4.
2. Install the thermostat.

Notice: Refer to Fastener Notice in the Preface section.

3. Install the thermostat housing and bolts.

Tighten
Tighten the bolts to 25 N·m (18 lb ft).




4. Install the lower intake manifold gaskets and seals (1).
5. Install the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .



6. Apply a small drop 8-10 mm (0.31-0.39 in) of RTV sealer to the 4 corners of the intake manifold to block joints (1). Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
7. Install the lower intake manifold.

Notice: Maximum gasket performance is achieved when using new fasteners, which contain a thread-locking patch. If the fasteners are not replaced, a thread locking chemical must be applied to the fastener threads. Failure to replace the fasteners or apply a thread-locking chemical MAY reduce gasket sealing capability.

8. Install NEW lower intake manifold bolts, if the bolts do not have the thread locking patch then apply sealer to the lower intake manifold bolt threads. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.




Notice: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.

9. Tighten the lower intake manifold bolts.

Tighten

1. Tighten the bolts on the first pass in sequence to 13 N·m (115 lb in).
2. Tighten the bolts (1, 2, 3, 4) on the second pass in sequence to 20 N·m (15 lb ft).
3. Tighten the bolts (5, 6, 7, 8) on the final pass in sequence to 25 N·m (18 lb ft).



10. Install the heater inlet pipe to the lower intake manifold.
11. Install the heater inlet pipe nut.

Tighten
Tighten the nut to 25 N·m (18 lb ft).




12. Connect the heater inlet hose (1) quick connect.



13. Install the radiator inlet hose to the thermostat housing.
14. Position the radiator inlet hose clamp at the thermostat housing.
15. Install the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement .
16. Install the left and right valve rocker arm covers. Refer to Valve Rocker Arm Cover Replacement - Left Side and Valve Rocker Arm Cover Replacement - Right Side .
17. Install the upper intake manifold. Refer to Upper Intake Manifold Replacement .