80. Intake Manifold Installation - Lower
Intake Manifold Installation - Lower1. Apply sealer GM P/N 12378479 or the equivalent at the engine block-to-lower intake manifold mating surface.
Ensure that the bead meets the following conditions:
- 2.0 - 3.0 mm (0.08 - 0.12 inch) wide
- 3.0 - 5.0 mm (0.12 - 0.20 inch) thick
2. Install the lower intake manifold.
Notice: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.
3. Apply sealer GM P/N 12345382 or the equivalent to the lower intake manifold bolt threads.
Notice: Refer to Fastener Notice in Service Precautions.
4. Install the lower intake manifold bolts.
4.1. Tighten the lower intake manifold bolts in sequence to 7 Nm (62 inch lbs.) on the first pass.
4.2. Tighten the lower intake manifold bolts in sequence to 13 Nm (115 inch lbs.) on the final pass.
5. Install the heater inlet pipe stud.
- Tighten the heater inlet pipe stud to 50 Nm (37 ft. lbs.).
6. Install the heater inlet pipe.
7. Install the heater inlet pipe nut.
- Tighten the heater inlet pipe nut to 25 Nm (18 ft. lbs.).
Important: Do not press on the fuel pressure regulator valve when installing the fuel injector rail assembly.
8. Install the fuel injector rail assembly.
8.1. Install the fuel injector O-rings using GM P/N 1051885 or the equivalent.
8.2. Install the injector nozzles into the lower intake manifold injector bores.
8.3. Press on the injector rail using the palms of both hands until the injectors are fully seated.
9. Install the fuel injector rail bolts.
- Tighten the fuel injector rail bolts to 10 Nm (89 inch lbs.).
10. Install the fuel feed and return pipe retaining clip.
11. 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.).