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

1. Remove the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 5.7 L.
2. Remove the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 5.7 L.
3. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information
4. Remove the transmission fluid level indicator tube bolt.
5. Lower the vehicle.



6. Remove the accelerator control cable bracket nut.
7. Remove the accelerator control cable and cruise control servo bracket.



8. Remove the positive crankcase ventilation (PCV) tube from the right rocker arm cover and throttle body.



9. Remove the PCV valve pipe from the left rocker arm cover.



10. Remove the PCV valve pipe strap nut.
11. Remove the PCV valve pipe from the right rocker arm cover and intake manifold.



12. Disconnect the vapor line from the evaporative emission (EVAP) canister purge solenoid valve (6).



13. Disconnect the EVAP canister purge solenoid valve electrical connector (5).



14. Remove the EVAP canister purge tube from the following:

•	Intake manifold

•	EVAP canister purge solenoid valve




15. Remove the EVAP canister purge solenoid valve (with bracket) from the intake manifold.



16. Disconnect the knock sensor harness electrical connector.
17. Remove the knock sensor wire harness connector (1) from the fuel rail stop bracket (2).



18. Disconnect the secondary air injection (AIR) vacuum control solenoid valve electrical connector.



19. Disconnect the AIR shut off valve vacuum harness from the following:

•	AIR shut off valve

•	Vacuum tee

20. Remove the AIR vacuum control solenoid valve (with bracket) from the intake manifold.
21. Remove the power brake booster vacuum hose from the vacuum port.



22. Disconnect the manifold absolute pressure (MAP) sensor electrical connector (1).
23. Disconnect the vacuum hose (2) from the tee on the rear vacuum port.



24. Remove the MAP sensor from the rear of the intake manifold.



25. Remove the intake manifold bolts (1) and fuel rail stop bracket (2).



26. Remove the intake manifold.



27. Remove the intake manifold-to-cylinder head gaskets (1).
28. Discard the gaskets.
29. Clean and inspect the intake manifold. Refer to Intake Manifold Cleaning and Inspection in Engine Mechanical - 5.7 L Unit Repair.

1. Install NEW intake manifold-to-cylinder head gaskets (1).



2. Install the intake manifold.



3. Apply threadlock GM P/N 12345382,(Canadian P/N 10953489), or equivalent to the threads of the intake manifold bolts (1).

Caution: The fuel rail stop bracket must be installed onto the engine assembly. The stop bracket serves as a protective shield for the fuel rail in the event of a vehicle frontal crash. If the fuel rail stop bracket is not installed and the vehicle is involved in a frontal crash, fuel could be sprayed possibly causing a fire and personal injury from burns.

4. Install the fuel rail stop bracket (2).




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.

5. 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).



6. Install the MAP sensor to the rear of the intake manifold.



7. Connect the vacuum hose (2) to the tee on the rear vacuum port.
8. Connect the MAP sensor electrical connector (1).
9. Install the power brake booster vacuum hose to the vacuum port.



10. Install the AIR vacuum control solenoid valve (with bracket) to the intake manifold.
11. Connect the AIR shut off valve vacuum harness to the following:

•	AIR shut off valve

•	Vacuum tee




12. Connect the AIR vacuum control solenoid valve electrical connector.



13. Install the knock sensor wire harness connector (1) to the fuel rail stop bracket (2).
14. Connect the knock sensor harness electrical connector.



15. Install the EVAP canister purge solenoid valve (with bracket) to the intake manifold.
16. Connect the vapor line to the EVAP canister purge solenoid valve.



17. Install the EVAP canister purge tube to the following:

•	Intake manifold

•	EVAP canister purge solenoid valve




18. Connect the EVAP canister purge solenoid valve electrical connector (5).



19. Connect the vapor line to the evaporative emission (EVAP) canister purge solenoid valve (6).



20. Install the PCV valve pipe to the right rocker arm cover and intake manifold.
21. Install the PCV valve pipe strap nut.

Tighten
Tighten the PCV strap nut to 12 N·m (106 lb in).




22. Install the PCV valve pipe to the left rocker arm cover and throttle body.



23. Install the PCV tube to the right rocker arm cover.



24. Install the accelerator control cable and cruise control servo bracket.
25. Install the accelerator control cable bracket nut.

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

26. Raise the vehicle.



27. Install the transmission fluid level indicator tube bolt.
28. Lower the vehicle.
29. Install the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 5.7 L.
30. Install the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 5.7 L.