67. Upper Intake Manifold Cleaning and Inspection

Upper Intake Manifold Cleaning and Inspection




1. Remove the throttle body bolts and nuts.
2. Remove the throttle body.
3. Remove the throttle body studs, if required.
4. Remove the manifold absolute pressure (MAP) sensor (1).
5. Remove the evaporative emission (EVAP) purge valve bolt (2).
6. Remove the EVAP purge valve (3).




7. Remove the EVAP purge valve isolator, if equipped.





Note: If at any time the intake manifold tuning valve blade becomes separated from the actuator, DO NOT cycle the actuator. Cycling the actuator without the blade attached will offset the calibration, and the entire intake manifold tuning valve assembly will need to be replaced.

8. Remove the intake manifold tuning valve bolts.
9. Remove the intake manifold tuning valve.

Warning

Bodily injury may occur if the cleaning solvent is inhaled or exposed to the skin.

10. Clean the intake manifold with solvent.
11. Dry the intake manifold with compressed air.
12. Inspect all gasket mating surfaces for nicks or cracks and replace if necessary.
13. Inspect the intake manifold tuning valve seal for damage. Inspect the intake manifold tuning valve blade for cracks, missing material, or looseness. The tuning valve blade attachment to the motor should be tight, with no slack present. Replace if necessary.




14. Apply lubricant GM P/N 1051344 (Canadian P/N 993037) to the valve shaft (1).




15. Install the intake manifold tuning valve, ensuring proper alignment is achieved. Failure to do so may result in the valve getting jammed or stuck in the intake manifold.

Caution: Refer to Fastener Caution (Fastener Caution).

16. Install the intake manifold tuning valve bolts and tighten to 10 Nm (89 lb in).




17. Install the EVAP purge valve isolator, if equipped.




18. Inspect the EVAP purge valve seal for damage and replace if necessary.
19. Install the EVAP purge valve (3).
20. Install the EVAP purge valve bolt (2) and tighten to 16 Nm (12 lb ft).





Note: Ensure that the EVAP purge valve isolator is installed properly as shown, with the isolator covering the top and bottom of the purge valve bolt hole flange. Failure to do so may cause improper EVAP purge valve operation.

21. Inspect the MAP sensor seal for damage and replace if necessary.
22. Install the MAP sensor.
23. Install the throttle body studs, if required, and tighten to 6 Nm (53 lb in).
24. Inspect the throttle body seal for damage and replace if necessary.
25. Install the throttle body.
26. Apply thread lock GM P/N 12345382 (Canadian P/N 10953489) to the throttle body bolt and nut threads.
27. Install the throttle body bolts and nuts and tighten to 10 Nm (89 lb in).