Intake Manifold Replacement - Lower

Intake Manifold Replacement - Lower

^ Tools Required
- J 36660-A Torque Angle Meter

Removal Procedure

Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.





1. Remove the upper intake manifold.
2. Remove the engine left side valve rocker arm cover.
3. Remove the engine right side valve rocker arm cover.
4. Disconnect the wiring harness from the Engine Coolant Temperature (ECT) sensor.

Important: Use masking tape or another appropriate method in order to identify each fuel injector wiring harness connector cylinder number.





5. Disconnect and remove the fuel injector, Manifold Air Pressure (MAP) and ECT wiring harness.
6. Remove the fuel feed and return pipe from the fuel injector rail.





7. Remove the fuel injector rail.

Important: Do NOT disconnect the power steering pipes or hoses from the power steering pump.

8. Remove the power steering pump from the front engine cover and reposition aside.
9. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition aside.
10. Disconnect the inlet radiator hose from the engine.





11. Disconnect the thermostat bypass hose from the lower intake manifold pipe.





12. Remove the lower intake manifold bolts.





13. Remove the lower intake manifold.
14. Loosen the valve rocker arms and remove the push rods.





15. Remove the lower intake manifold gaskets and seals.
16. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
17. Clean and inspect the lower intake manifold.
18. If you are replacing the lower intake manifold, remove the ECT sensor.
19. If you are REPLACING the lower intake manifold, remove the thermostat.

Installation Procedure





1. Apply 8 - 12 mm (0.08 - 0.11 inch) bead of RTV Sealer GM P/N 12345739 or equivalent on each ridge where front and rear of the lower intake manifold contact the engine block (1).
2. Install the lower intake manifold gaskets.
3. Install the push rods and tighten the valve rocker arms.

Notice: Refer to Fastener Notice in Service Precautions.

4. Install the valve rocker arm bolts.
Use the J 36660-A to tighten the bolts to 19 Nm (14 ft. lbs.) plus 30 degrees.





5. Install the lower intake manifold.
6. Install the lower intake manifold bolts.





7. Tighten the lower intake manifold bolts.

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

8. Apply sealer GM P/N 12345382 or the equivalent to the lower intake manifold bolt threads.





9. Install the lower intake manifold bolts.
Tighten the bolts in sequence to 13 Nm (115 inch lbs.).





10. Connect the thermostat bypass hose to the lower intake manifold pipe.
11. Connect the inlet radiator hose from the engine.





12. Connect the heater inlet pipe and heater hose to the lower intake manifold.
13. Install the power steering pump to the front engine cover.





14. Install the fuel injector rail.
15. Connect the fuel feed and return pipe to the fuel injector rail.

Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.





16. Install and connect the fuel injector, MAP and ECT wiring harness.
17. Install the wiring harness to the ECT sensor.
18. Install the engine right side valve rocker arm cover.
19. Install the engine left side valve rocker arm cover.





20. Install the upper intake manifold.