88. Lower Intake Manifold Installation

Lower Intake Manifold Installation





Note: 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.

1. With gaskets and seals in place apply a small drop 8-10 mm (0.31-0.39 in) of room temperature vulcanizing (RTV) sealer GM P/N 12378521 (Canadian P/N 88901148) or equivalent to the 4 corners of the intake manifold to block joints (1).

Note: To ensure proper lower intake manifold orientation during installation, make sure the intake port marked 1 faces the front of the engine.

2. Install the lower intake manifold.





Caution: Maximum gasket performance is achieved when using new fasteners, which contain a thread-locking patch. If the fasteners are not replaced, a thread locking chemical must be applied to the fastener threads. Failure to replace the fasteners or apply a thread-locking chemical MAY reduce gasket sealing capability.

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

3. Apply sealer GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the lower intake manifold bolt threads.

Caution: Refer to Fastener Caution (Fastener Caution).

4. Install the new lower intake manifold bolts if applicable, in sequence.

1. Tighten the lower intake manifold bolts in sequence to 7 Nm (62 lb in) on the first pass.
2. Tighten the lower intake manifold bolts (1, 2, 3, 4) in sequence to 16 Nm (12 lb ft) on the final pass.
3. Tighten the lower intake manifold bolts (5, 6, 7, 8) in sequence to 25 Nm (18 lb ft) on the final pass.




5. Inspect the fuel rail, and fuel injectors for damage and replace if necessary.
6. Install NEW lower fuel injector O-rings.
7. Lubricate the fuel injector O-rings using GM P/N 12345616 (Canadian P/N 993182) or equivalent.

Note: To ensure proper fuel rail orientation during installation, make sure the fuel feed pipe faces the rear of the engine.

8. Install the injector nozzles into the lower intake manifold injector bores.
9. Press on the injector rail using the palms of both hands until the injectors are fully seated.
10. Install the fuel injector rail bolts and tighten to 10 Nm (89 lb in).
11. Connect the coolant temperature sensor (1).
12. Connect the camshaft position (CMP) sensor (2).