Intake Manifold Replacement (Lower)

REMOVAL PROCEDURE

NOTICE: The two bolts which fasten the lower intake manifold to the cylinder head are accessible only after the upper intake is removed. The bolts are located in the right front and left rear corners of the lower intake manifold. Remove the upper intake manifold to service the lower intake.

1. Remove the upper intake manifold.
2. Remove the generator braces.
3. Remove the generator.
4. Remove the drive belt tensioner with mounting bracket and the heater water bypass inlet pipe.
5. Disconnect the EGR valve outlet pipe from the lower intake manifold.





6. Remove the radiator inlet hose from the water outlet housing.





7. Disconnect the Engine Coolant Temperature (ECT) sensor wiring harness connector.





8. Remove the generator bracket bolts.
9. Remove the generator bracket.
10. Remove the Evaporative Emissions (EVAP) canister purge solenoid valve.





11. Remove the lower intake manifold bolts.
12. Remove the lower intake manifold.





13. Remove the lower intake manifold seals.





14. Remove the lower intake manifold gaskets.





15. If replacing the lower intake manifold, remove the water outlet housing bolts, water outlet housing, gasket and thermostat.





16. If replacing the lower intake manifold, remove the Engine Coolant Temperature (ECT) sensor.
17. Inspect the flatness of inlet flanges.
18. Clean the engine block.
19. Clean the cylinder block, heads, and the intake manifold sealing surface with a suitable solvent.
20. Clean the intake manifold bolts and bolt holes of adhesive compound.

INSTALLATION PROCEDURE





1. If removed, install the Engine Coolant Temperature (ECT) sensor.
^ Tighten the Engine Coolant Temperature (ECT) sensor to 25 Nm (18 ft. lbs.).

NOTICE: Refer to Fastener Notice in Service Precautions. Fastener Notice





2. If removed, install the thermostat, gasket and water outlet housing.
3. Install the water outlet housing bolts.
^ Tighten the water outlet housing bolts to 27 Nm (20 ft. lbs.).





4. Install the lower intake manifold gaskets.
5. Apply sealer GM P/N 12345336 or equivalent to the ends of the intake manifold seals.





6. Install the lower intake manifold seals.





7. Install the lower intake manifold.





8. Install the lower intake manifold bolts (1-12). Apply thread lock compound GM P/N 12345382 or equivalent to the two hidden bolts and ensure they are installed.
^ Tighten the lower intake manifold bolts in sequence to 15 Nm (11 ft. lbs.).

9. Install the generator bracket.





10. Install the generator brace bracket bolts.
^ Tighten the generator brace bracket bolts to 50 Nm (37 ft. lbs.).

11. Install the evaporative emissions (EVAP) canister purge solenoid valve.





12. Connect the Engine Coolant Temperature (ECT) sensor wiring harness connector.





13. Install the radiator inlet hose to the water outlet housing.





14. Install the drive belt tensioner mounting bracket and the heater water bypass inlet pipe.
15. Install the EGR valve outlet pipe to the lower intake manifold.
^ Tighten the EGR valve outlet pipe bolt to 29 Nm (21 ft. lbs.).

16. Install the generator.
17. Install the generator braces.
18. Install the upper intake manifold.