Important: The intake manifold, throttle body, fuel rail, and injectors may be removed as an assembly. If not servicing the individual components, remove the manifold as a complete assembly.

1. Remove the engine sight shield and retainer. Refer to Upper Intake Manifold Sight Shield Replacement .
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief in Engine Controls - 4.8L, 5.3L, and 6.0L.
3. Disconnect the cruise control cable from the throttle blade stud.
4. Remove the cruise control cable from the bracket.



5. Remove the accelerator control cable from the throttle blade.
6. Remove the accelerator control cable from the bracket.



7. Disconnect the following electrical connectors:

•	Main ignition coil harness (2).

•	Fuel injectors (3)

8. Disconnect the wiring harness clips (1) from the fuel rail.



9. Disconnect the following electrical connectors:

•	Main ignition coil harness (1)

•	Fuel injectors (3)

•	Exhaust gas recirculation (EGR) valve (4)

10. Disconnect the harness clips (2) from the fuel rail.



11. Disconnect the following electrical connectors:

•	Manifold absolute pressure (MAP) sensor (1)

•	Knock sensor (2)

12. Remove the knock sensor harness electrical connector from the intake manifold.
13. Set the electrical harness aside.



14. Disconnect the following electrical connectors:

•	Throttle position (TP) sensor, if equipped

•	Electronic throttle control (ETC) motor, if equipped

•	Idle air control (IAC) valve




15. Disconnect the following electrical connectors:

•	Purge solenoid (1)

•	Generator (3)

16. Remove the wiring harness bracket nut.
17. Remove the harness bracket from the stud.
18. Reposition the engine wiring harness.



19. Reposition the coolant air bleed hose at the throttle body.
20. Remove the coolant air bleed hose from the throttle body.



21. Reposition the radiator vent inlet hose clamp at the throttle body.
22. Remove the radiator vent inlet hose from the throttle body.



23. Remove the positive crankcase ventilation (PCV) hose from the throttle body and rocker arm cover.



24. Remove the PCV hose (with valve) from the intake manifold and rocker arm cover.



25. Remove the following EGR pipe bolts:

•	Intake manifold (1)

•	Cylinder head (2)

•	Exhaust manifold (3)

26. Remove the EGR pipe (with valve).
27. Remove the EGR pipe gasket from the exhaust manifold.



28. If equipped, remove the vacuum brake booster hose from the rear of the intake manifold.



29. Remove the evaporative emission (EVAP) purge solenoid vent tube by performing the following:

29.1.

Remove the EVAP tube end (2) from the solenoid (1).

29.2.

Squeeze the EVAP pipe quick connect fitting (3) retainer together.

29.3.

Remove the EVAP tube end (3) from the vapor pipe.

30. Disconnect the fuel line quick connect fittings. Refer to Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service in Engine Controls - 4.8L, 5.3L, and 6.0L.



31. Remove the intake manifold bolts.
32. Remove the intake manifold.



33. Remove the intake manifold gaskets (1) from the intake manifold.
34. Discard the old intake manifold gaskets.
35. Clean the gasket surfaces of the EGR pipe and the exhaust manifold.
36. If replacement of the intake manifold is required, remove the following components:

•	Throttle body. Refer to Throttle Body Removal in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.

•	Fuel rail and injectors. Refer to Fuel Rail and Injectors Removal in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.




37. If replacement of the intake manifold is required, remove the MAP sensor (1).



38. If replacement of the intake manifold is required, remove the accelerator control cable bracket bolts (1) and bracket (2).



39. If replacement of the intake manifold is required, remove the EVAP solenoid bolt (2), solenoid (3) and isolator (1).

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

1. If replacement of the intake manifold was required, install the EVAP solenoid isolator (1), solenoid (3) and bolt (2) to the NEW intake manifold.

Tighten
Tighten the EVAP solenoid bolt to 10 N·m (89 lb in).




2. If replacement of the intake manifold was required, install the accelerator control cable bracket (2) and bolts (1) to the NEW intake manifold.

Tighten
Tighten the accelerator control cable bracket bolts to 10 N·m (89 lb in).




3. If replacement of the intake manifold was required, install the MAP sensor (1) to the NEW intake manifold.
4. If replacement of the intake manifold was required, install the following components to the NEW intake manifold:

•	Throttle body. Refer to Throttle Body Installation in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.

•	Fuel rail and injectors. Refer to Fuel Rail and Injectors Installation in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.




5. Install NEW intake manifold gaskets (1) to the intake manifold.



6. Install the intake manifold.
7. Apply a 5 mm (0.20 in) band of threadlock GM P/N 12345382 or equivalent to the threads of the intake manifold bolts.



8. Install the intake manifold bolts.

Tighten

1. Tighten the intake manifold bolts a first pass in sequence to 5 N·m (44 lb in).
2. Tighten the intake manifold bolts a final pass in sequence to 10 N·m (89 lb in).



9. Install the PCV hose (with valve).



10. Install the vacuum brake booster hose to the rear of the intake manifold, if equipped.



11. Position a NEW EGR pipe gasket on the exhaust manifold.
12. Install the EGR pipe (with valve).
13. Install the following EGR pipe bolts until snug:

•	Intake manifold (1)

•	Cylinder head (2)

•	Exhaust manifold (3)

14. Tighten the EGR pipe bolts.

Tighten

•	Tighten the EGR valve pipe-to-intake manifold bolts to 10 N·m (89 lb in).

•	Tighten the EGR valve pipe-to-cylinder head bolts to 50 N·m (37 lb ft).

•	Tighten the EGR valve pipe-to-exhaust manifold bolts to 30 N·m (22 lb ft).

15. Route the electrical harness into position over the engine.



16. Connect the knock sensor harness electrical connector to the intake manifold.
17. Connect the following electrical connectors.

•	MAP sensor (1)

•	Knock sensor (2)




18. Connect the following electrical connectors:

•	Main ignition coil harness (1)

•	Fuel injectors (3)

•	EGR valve (4)

19. Connect the harness clips (2) to the fuel rail.



20. Connect the following electrical connectors:

•	Main ignition coil harness (2).

•	Fuel injectors (3)

21. Connect the wiring harness clips (1) to the fuel rail.



22. Install the accelerator control cable to the bracket.
23. Install the accelerator control cable to the throttle blade.



24. Install the cruise control cable to the bracket.
25. Connect the cruise control cable to the throttle blade stud.
26. Install the engine sight shield and retainer. Refer to Upper Intake Manifold Sight Shield Replacement .