Lower Intake Manifold Installation

WARNING: This page is about a different variant/trim than selected.

Fig 1: Installing Lower Intake Manifold

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: All gasket-mating surfaces need to be free of oil and foreign material. Use P/N 12378392 or equivalent to clean surfaces.

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

Fig 2: Lower Intake Manifold Bolt Tightening Sequence

Courtesy of GENERAL MOTORS CORP.

NOTE: 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.

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

Apply sealer P/N 21485277 or equivalent to the lower intake manifold bolt threads.

NOTE: Refer to Fastener Notice in Cautions and Notices.

Install the new lower intake manifold bolts if applicable, in sequence.
Tighten:
1. Tighten the lower intake manifold bolts in sequence to 13 N.m (115 lb in) on the first pass.
2. Tighten the lower intake manifold bolts (1, 2, 3, 4) in sequence to 20 N.m (15 lb ft) on the final pass.
3. Tighten the lower intake manifold bolts (5, 6, 7, 8) in sequence to 25 N.m (18 lb ft) on the final pass.

Fig 3: Removing/Installing Heater Inlet Pipe Nut

Courtesy of GENERAL MOTORS CORP.

Inspect the heater inlet pipe and seal for damage and replace if necessary.
Install the heater inlet pipe stud, if necessary.
Tighten: Tighten the heater inlet pipe stud to 35 N.m (26 lb ft).
Install the heater inlet pipe.
Install the heater inlet pipe nut.
Tighten: Tighten the heater inlet pipe nut to 25 N.m (18 lb ft).

Fig 4: Removing/Installing Fuel Injector And Manifold Air Pressure (MAP) Wiring Harness

Courtesy of GENERAL MOTORS CORP.

Inspect the fuel rail, fuel injectors, and fuel injector O-rings for damage and replace if necessary.
Lubricate the fuel injector O-ring using engine oil P/N 21007414.
Install the injector nozzles into the lower intake manifold injector bores.
Press on the injector rail using the palms of both hands until the injectors are fully seated.
Install the fuel injector rail bolts.
Tighten: Tighten the fuel injector rail bolts to 10 N.m (89 lb in).