Intake Manifold Installation (Lower)

1. Apply sealer GM P/N 12345739 or equivalent at the engine block-to-lower intake manifold mating surface. The bead should be 2.0 - 3.0 mm (0.08 - 0.12 inch) wide and 3.0 - 5.0 mm (0.12 - 0.20 inch) thick.
2. Install the lower intake manifold.





3. Apply sealer GM P/N 12345382 or equivalent to the lower intake manifold bolt threads.

Notice: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.

4. Install the lower intake manifold bolts.
^ Tighten the bolts in sequence to 13 Nm (115 inch lbs.).

Notice: Refer to Fastener Notice in Service Precautions.





5. Install the heater inlet pipe.
6. Install the heater inlet pipe nut.
^ Tighten the heater inlet pipe nut to 25 Nm (18 ft. lbs.).





7. Install the fuel injector rail assembly.
7.1. Lubricate the fuel injector O-rings with GM P/N 1051885 or equivalent.
7.2. Install the injector nozzles into the lower intake manifold injector bores.
7.3. Press on the injector rail with the palms of both hands until the injectors are fully seated.

Important: Do not press on the fuel pressure regulator valve when installing the fuel injector rail assembly.

8. Install the fuel injector rail bolts.
^ Tighten the fuel injector rail bolts to 10 Nm (89 inch lbs.).





9. Install the fuel feed and return pipe retaining clip.
10. Install the fuel feed and return pipe retaining clip bolt.
^ Tighten the fuel feed and return pipe retaining clip bolt to 8 Nm (71 inch lbs.).