Lower Intake Manifold Replacement

REMOVAL PROCEDURE

^ Tools Required
- J 28467-360 Engine Support Fixture
- J 23600-8 Torque Angle Meter

CAUTION: Refer to Battery Disconnect Caution in Service Precautions.






1. Disconnect the negative battery cable.
2. Depressurize the fuel system. Refer to Fuel System Pressure Relief in Engine Fuel.
3. Remove the top half of the air cleaner assembly.
4. Drain and recover the cooling system. Refer to Draining, Flushing and Filling the Cooling System in Cooling and Radiator.
5. Remove the EGR pipe from the exhaust manifold.
6. Remove the drive belt. Refer to Accessory Drive Belt Replacement.
7. Remove the brake vacuum pipe at the plenum.
8. Remove the power steering lines at the generator bracket.
9. Remove the generator. Refer to Generator in Charging System.






10. Remove the secondary ignition wires from the spark plugs.
11. Remove the secondary ignition wires from the harness at the plenum.






12. Remove the following components at the same time:
^ Electronic ignition coil and module assembly.
^ EVAP canister purge solenoid.

13. Remove the following upper engine wiring connectors:
^ Throttle Position (TP) sensor.
^ IAC sensor.
^ Injector harness.
^ Engine Coolant Temperature (ECT) sensor.
^ MAP sensor.
^ Camshaft Position (CMP) sensor.






14. Remove the following vacuum lines:
^ Vacuum Modulator.
^ Fuel Pressure Regulator.
^ PCV






15. Remove the MAP sensor from the upper intake manifold.






16. Remove the upper intake manifold bolts.
17. Remove the upper intake manifold.






18. Remove the fuel lines at the fuel rail and the bracket.
19. Install the J 28467-360.
20. Remove the engine mount assembly. Refer to Engine Mount Replacement.
21. Remove the power steering mounting bolts. Support the pump aside. Refer to Power Steering Pump in Power Steering Gear and Pump.






22. Remove the heater inlet pipe from the coolant outlet housing. Refer to Cooling and Radiator.






23. Remove the heater by-pass at the coolant pump and the cylinder head. Refer to Cooling and Radiator.
24. Remove the radiator hose at the heater outlet housing.
25. Remove the heater outlet housing. Refer to Cooling and Radiator.
26. Remove both of the valve rocker covers. Refer to Valve Rocker Arm Cover Replacement.

IMPORTANT: Retain the washers in the same orientation on the center bolts.






27. Remove the lower intake manifold bolts.
28. Remove the lower intake manifold.






29. Loosen the rocker arms.

IMPORTANT: Keep the pushrods in order. The pushrods must be installed in the original position.






30. Remove the pushrods.






31. Remove the intake gasket.
32. Inspect the flatness of the inlet flanges.
33. Clean the following items:
^ Gasket material from the mating surfaces.
^ Excess RTV sealant from the front and the rear ridges of the cylinder.
^ Block.
^ Sealing surfaces with degreaser.

INSTALLATION PROCEDURE






1. Place a 2-3 mm bead of GM RTV sealer P/N 12345739, or equivalent on each ridge where the front and the rear of the intake manifold contact the block.
2. Install the intake manifold gasket.






3. Install the pushrods.
Install the rocker arm bolts.
^ Tighten the bolts to 10 Nm (124 inch lbs.) + 30°.

NOTICE: Refer to Fastener Notice in Service Precautions.






3.1. Install the pushrods in their original location.
3.2. Coat the ends of the pushrods with prelube GM P/N 1052356, or equivalent.
3.3. Intake pushrods are 144 mm (5.75 inch).
3.4. Exhaust pushrods are 152.5 mm (6.0 inch).
3.5. Ensure that the pushrods seat in the lifter.
4. Install the lower intake manifold.






5. Install the lower intake manifold bolts.






6. Apply sealant GM P/N 12345382 to the threads of the bolts.

6.1. Tighten the vertical bolts to 13 Nm (115 inch lbs.).
6.2. Tighten the diagonal bolts to 13 Nm (115 inch lbs.).
7. Install the front valve rocker cover. Refer to Valve Rocker Arm Cover Replacement.
8. Install the heater outlet housing. Refer to Cooling and Radiator.
9. Install the radiator hose to the thermostat housing.
10. Install the heater inlet pipe to the thermostat housing.






11. Install the heater by-pass pipe at the water pump and the cylinder head. Refer to Cooling and Radiator.






12. Install the power steering pump. Refer to Power Steering Pump in Power Steering Pump and Gear.
13. Loosely, install the drive belt. Refer to Accessory Drive Belt Replacement.
14. Install the engine mount assembly. Refer to Engine Mount Replacement.
15. Remove the engine support fixture.
16. Install the fuel lines to the fuel rail and the bracket.






17. Install the upper intake manifold.
18. Install the upper intake manifold bolts.
^ Tighten the bolts to 25 Nm (18 ft. lbs.).

NOTICE: Refer to Fastener Notice in Service Precautions.

19. Install the MAP sensor.
20. Connect the following vacuum lines:
^ Vacuum Modulator.
^ Fuel Pressure Regulator.
^ PCV

21. Install the following upper engine wiring connectors:
^ Throttle Position (TP) sensor.
^ IAC.
^ Injector harness.
^ Engine Coolant Temperature (ECT) sensor.
^ MAP sensor.
^ Camshaft Position (CMP) sensor.

22. Install the following components:
^ EVAP canister purge solenoid.
^ Electronic ignition coil and module assembly.

23. Install the generator. Refer to Generator in Charging System.
24. Install the power steering line at the generator bracket.
25. Install the drive belt. Refer to Accessory Drive Belt Replacement.






26. Install the secondary ignition wires to the spark plugs.
27. Install the secondary ignition wires to the harness at the plenum.






28. Install the EGR pipe to the exhaust manifold..
29. Install the following items to the throttle body:
^ Throttle body cable.
^ Cruise control cable.

30. Install the top half of the air cleaner assembly.
31. Install the brake vacuum pipe.
32. Install the cables to the throttle body.,
33. Fill the cooling system. Refer to Draining, Flushing and Filling the Cooling System in Cooling and Radiator.
34. Connect the negative battery cable.
35. Inspect for proper fluid levels.
36. Check for leaks.