Upper Intake Manifold Replacement
Removal ProcedureImportant: It is not necessary to remove the upper intake manifold in order to remove the lower intake manifold.
1. Disconnect the PCV hose from the air cleaner outlet duct.
2. Remove the air cleaner outlet duct from the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement.
3. Disconnect the accelerator control cable from the throttle shaft and the accelerator cable bracket at the side of the throttle body. Refer to Accelerator Controls Cable Replacement.
4. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket at the side of the throttle body. Refer to Cruise Control Cable Replacement.
5. Remove the engine wiring harness clip from the accelerator control cable bracket.
6. Remove the accelerator control cable bracket with the accelerator control cable and the cruise control cable from the throttle body.
7. Move and secure the accelerator control cable and the cruise control cable out of the way.
8. Disconnect the secondary Air Injection (AIR) crossover pipe from the AIR pipe assemblies, if equipped.
9. Remove the AIR crossover pipe, if equipped.
10. Disconnect the following electrical connections:
^ The A/C compressor clutch (1), if equipped
^ The A/C pressure switch (4), if equipped
^ The EGR valve (2)
11. Disconnect the following electrical connections:
^ The Throttle Position (TP) sensor (1)
^ The Idle Air Control (IAC) motor (2)
^ The fuel meter body assembly connector (3)
12. Disconnect the following electrical connections:
^ The manifold absolute pressure (MAP) sensor (2)
^ The EVAP canister purge solenoid valve (1)
13. Remove the two nuts holding the engine wiring harness bracket to the upper intake manifold studs.
14. Remove the engine wiring harness bracket from the studs.
15. Remove the nut holding the engine wiring harness bracket to the stud at the EVAP canister purge solenoid valve.
16. Remove the nut and the ground wire from the engine wiring harness bracket stud at the rear of the right cylinder head.
17. Remove the stud holding the engine wiring harness bracket.
18. Move the engine wiring harness and the engine wiring harness brackets aside.
19. Remove the EVAP canister purge solenoid valve. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement.
20. Remove the PCV valve hose assembly form the intake manifold and the valve rocker arm cover.
21. Disconnect the power brake booster vacuum hose from the intake manifold.
22. Remove the accelerator control cable bracket from the intake manifold and the throttle body.
23. Remove the fuel lines from the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement (Engine Compartment).
24. Remove the studs for the upper intake manifold.
25. Remove the upper intake manifold.
26. Remove the upper intake manifold gasket from the groove.
27. Discard the gasket.
28. Remove the seal (O-ring) from the fuel meter body assembly.
29. Discard the seal.
Important: Do not immerse the assembled upper intake manifold in cleaning solvent.
30. Clean all sealing surfaces and the inside of the upper intake manifold with a shop towel and cleaning solvent.
31. Inspect the upper intake manifold for the following:
^ Cracks or other damage to the exterior
^ Cracking or damage to the gasket grooves
^ Loose or damaged bolt hole thread inserts
32. If replacing the upper intake manifold, turn and remove the power brake booster vacuum tube fitting from the upper intake manifold.
33. Remove and discard the seal (O-ring).
34. If replacing the upper intake manifold, turn and remove the PCV valve cover from the upper intake manifold.
35. Remove and discard the seal (O-ring).
36. Remove the throttle body if replacing the upper intake manifold. Refer to Throttle Body Assembly Replacement.
37. Remove the MAP sensor if replacing the upper intake manifold. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement.
Installation Procedure
1. Install the throttle body, if removed. Refer to Throttle Body Assembly Replacement.
2. Install the MAP sensor, if removed. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement.
3. Install the PCV valve cover, if removed, using the following procedure:
3.1. Install a NEW seal (O-ring) on the PCV valve cover.
3.2. Lubricate the seal with clean engine oil.
3.3. Install the PCV valve cover in the upper intake manifold.
3.4. Turn and lock the PCV valve cover in position.
4. install the power brake booster vacuum tube fitting, if removed, using the following procedure:
4.1. Install a NEW seal (O-ring) on the power brake booster vacuum tube fitting.
4.2. Lubricate the seal with clean engine oil.
4.3. Install the power brake booster vacuum tube fitting in the upper intake manifold.
4.4. Turn and lock the power brake booster vacuum tube fitting in position.
5. Install a NEW seal on the fuel meter body assembly.
6. Lubricate the seal with clean engine oil.
7. Install a NEW upper intake manifold to lower intake manifold gasket in the groove of the upper intake manifold.
8. Install the upper intake manifold onto the lower intake manifold.
9. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the upper intake manifold attaching bolts.
Notice: Refer to Fastener Notice in Service Precautions.
10. Install the upper intake manifold attaching studs.
10.1. Tighten the upper intake manifold attaching studs on the first pass to 5 Nm (44 inch lbs.).
10.2.Tighten the upper intake manifold attaching studs on the final pass to 9 Nm (80 inch lbs.).
11. Install the fuel lines to the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement (Engine Compartment).
12. Install the EVAP canister purge solenoid valve. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement.
13. Install the accelerator control cable bracket to the throttle body and the intake manifold.
Tighten the accelerator control cable bracket studs and nuts to 12 Nm (106 inch lbs.).
14. Connect the PCV valve hose assembly to the intake manifold and the valve rocker arm cover.
15. Connect the power brake booster vacuum hose to the intake manifold.
16. Position the engine wiring harness and engine wiring harness brackets.
17. Install the stud holding the engine wiring harness bracket to the rear of the right cylinder head.
Tighten the engine wiring harness bracket stud to 25 Nm (18 ft. lbs.).
18. Install the nut holding the engine wiring harness bracket to the stud at the EVAP canister purge solenoid valve.
Tighten the engine wiring harness bracket nut to 9 Nm (80 inch lbs.).
19. Install the nut and the ground wire on the engine wiring harness bracket stud at the rear of the right cylinder head.
Tighten the ground wire nut to 16 Nm (12 ft. lbs.).
20. Install the engine wiring harness bracket on the upper intake manifold studs.
21. Install the engine wiring harness bracket nuts.
Tighten the engine wiring harness bracket nuts to 12 N m(106 inch lbs.).
22. Connect the following electrical connections:
^ The A/C compressor clutch (1), if equipped
^ The A/C pressure switch (4), if equipped
^ The EGR valve (2)
23. Connect the following electrical connections:
^ The throttle position (TP) sensor (1)
^ The idle air control (IAC) motor (2)
^ The fuel meter body assembly connector (3)
24. Connect the following electrical connections:
^ The manifold absolute pressure (MAP) sensor (2)
^ The EVAP canister purge solenoid valve (1)
25. Install the accelerator control cable bracket with the accelerator control cable and the cruise control cable and the nuts to the throttle body.
Tighten the accelerator control cable bracket nuts to 9 Nm (80 inch lbs.).
26. Install the engine wiring harness clip to the accelerator control cable bracket.
27. Install the cruise control cable, if equipped to the throttle shaft and the accelerator control cable bracket. Refer to Cruise Control Cable Replacement.
28. Install the accelerator control cable to the throttle shaft and the accelerator control cable bracket. Refer to Accelerator Controls Cable Replacement.
29. Connect the AIR crossover pipe to the AIR pipe assemblies.
30. Install the air cleaner outlet duct to the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement.
31. Connect the PCV hose to the air cleaner outlet duct.