Intake Manifold: Service and Repair

Intake Manifold Replacement

Removal Procedure

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.
2. Remove the fuel rail.
3. Raise and suitably support the vehicle. Refer to Vehicle Lifting
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.

Installation Procedure





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





2. Install the intake manifold.





3. Apply threadlock GM P/N 12345382 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 bums.

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

Notice: Refer to Fastener Notice in Service Precautions.





5. Install the intake manifold bolts
5.1. Tighten the intake manifold bolts a first pass in sequence to 5 Nm (44 inch lbs.).
5.2. Tighten the intake manifold bolts a final pass in sequence to 10 Nm (89 inch lbs.).





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 the PCV strap nut to 12 Nm (106 inch lbs.).





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 the accelerator control cable bracket nut to 10 Nm (89 inch lbs.).
26. Raise the vehicle.





27. Install the transmission fluid level indicator tube bolt.
28. Lower the vehicle.
29. Install the fuel rail.
30. Install the throttle body.