Intake Manifold Replacement - Lower

Intake Manifold Replacement- Lower
Removal Procedure





1. Disconnect the negative battery cable.
2. Remove the upper intake manifold.
3. Remove the left valve rocker arm cover.
4. Remove the right valve rocker arm cover.
5. Disconnect the Engine Coolant Temperature (ECT) sensor electrical connector.





6. Disconnect and remove the fuel injector and the Manifold Absolute Pressure (MAP) sensor wiring harnesses.





7. Remove the fuel pipe clip bolt.





8. Remove the fuel pipe clip.





9. Remove the fuel feed pipe from the fuel injector rail.





10. Remove the fuel return pipe from the fuel injector rail.





11. Remove the fuel injector rail.
12. Remove the power steering pump from the front engine cover and reposition.





13. Remove the heater inlet pipe nut.
14. Remove the heater inlet pipe with heater hose from the lower intake manifold and reposition.
15. Remove the radiator inlet hose from the engine.





16. Remove the thermostat bypass hose from the thermostat bypass pipe and lower intake manifold pipe.





17. Remove the lower intake manifold bolts.
18. Remove the lower intake manifold.
19. Remove the valve rocker arms and pushrods.





20. Remove the lower intake manifold gaskets and seals.
21. Clean the lower intake manifold gasket mating surfaces.
22. Remove and clean all the RTV sealant from the lower intake manifold and the engine block (1).





23. Remove the ECT sensor.





24. Remove the water outlet bolts.
25. Remove the water outlet.





26. Remove the thermostat.

Installation Procedure





1. Install the thermostat.





2. Install the water outlet.

Notice: Refer to Fastener Notice in Service Precautions.

3. Install the water outlet bolts.
^ Tighten the bolts to 25 Nm (18 ft. lbs.).





4. Install the ECT sensor.
^ Tighten the sensor to 25 Nm (18 ft. lbs.).

Important: All gasket-mating surfaces need to be free of oil, and foreign material. Use GM P/N 12346139 (Canadian P/N 10953463) or equivalent to clean surfaces.

5. Install the lower intake manifold gaskets.





6. With gaskets in place apply a small drop 8 - 10 mm (0.31 - 0.39 inch) of RTV Sealer, GM P/N 12346141 (Canadian P/N 89022195) or equivalent to the 4 corners of intake manifold to block joint (1).
7. Connect the 2 small drops with a bead of RTV sealer that is between 8-10 mm (0.31-0.39 in.) wide and 3.0-5.0 mm (0.12-0.20 in.) thick (2).
8. Install the valve rocker arms and pushrods.
9. Install the lower intake manifold.

Notice: Refer to Fastener Notice in Cautions and Notices.
Important: All lower intake manifold bolts need to be cleaned and free of any foreign material, only new bolts are to be used. Manufacturer recommends the center bolts be fully torqued before the diagonal bolts to assure proper seal ability. Lower intake manifold bolts in location 6 and 7 should be torqued to specification using a crows foot type tool.





10. Install NEW lower intake manifold bolts.

The torque specification is a 2-step process; tighten the vertical lower intake manifold bolts (the four middle ones) to 7 Nm (62 lb in). Tighten the diagonal lower intake manifold bolts (two on each end) to 7 Nm (62 lb in).Tighten the vertical lower intake manifold bolts (the four middle ones) to 13 Nm (115 lb in). Tighten the diagonal lower intake manifold bolts (two on each end) to 25 Nm (18 lb ft).






11. Install the thermostat bypass hose to the thermostat bypass pipe and lower intake manifold pipe.
12. Install the heater inlet pipe nut.
^ Tighten the nut to 25 Nm (18 ft. lbs.).
13. Install the radiator inlet hose to the engine.





14. Install the heater inlet pipe and heater hose to the lower intake manifold.
15. Install the power steering pump to the front engine cover.





16. Install the fuel injector rail.





17. Install the fuel return pipe to the fuel injector rail.





18. Install the fuel feed pipe to the fuel injector rail.





19. Install the fuel pipe clip.





20. Install the fuel pipe clip bolt.
^ Tighten the bolt to 8 Nm (71 inch lbs.).





21. Install and connect the fuel injector and the MAP sensor wiring harnesses.





22. Connect the ECT sensor electrical connector.
23. Install the right valve rocker arm cover.
24. Install the left valve rocker arm cover.
25. Install the upper intake manifold.
26. Connect the negative battery cable.
27. Inspect for leaks.