Intake Manifold Installation - Lower

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.

1. Install the lower intake manifold gaskets.
2. With gaskets in place apply a small drop 8-10 mm (0.31-0.39 in) of RTV sealer GM P/N 12346286 (Canadian P/N 10953472) or equivalent to the 4 corners of the intake manifold to block joint (1).
3. 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).
4. Install the lower intake manifold.
   Fig 1: Installing Lower Intake Manifold Gasket

   Courtesy of GENERAL MOTORS CORP.
   NOTE: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.
5. Apply sealer GM P/N 12345382 (Canadian P/N 10953489) or the equivalent to the lower intake manifold bolt threads.
   NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
6. Install the lower intake manifold bolts.

   Tighten 

   1. 6.1. Tighten the lower intake manifold bolts in sequence to 7 N.m (62 lb in) on the first pass.
   2. 6.2. Tighten the lower intake manifold bolts in sequence to 13 N.m (115 lb in) on the final pass.
   Fig 2: Identifying Lower Intake Manifold Bolt Tightening Sequence

   Courtesy of GENERAL MOTORS CORP.
7. Install the heater inlet pipe.
8. Install the heater inlet pipe nut.

   Tighten 

   Tighten the heater inlet pipe nut to 25 N.m (18 lb ft).

   Fig 3: Installing Heater Inlet Pipe

   Courtesy of GENERAL MOTORS CORP.

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

9. Install the fuel injector rail assembly.
   1. 9.1. Install the fuel injector O-rings using GM P/N 12345616 (Canadian P/N 993182) or the equivalent.
   2. 9.2. Install the injector nozzles into the lower intake manifold injector bores.
   3. 9.3. Press on the injector rail using the palms of both hands until the injectors are fully seated.
10. Install the fuel injector rail bolts.

    Tighten 

    Tighten the fuel injector rail bolts to 10 N.m (89 lb in).

    Fig 4: Installing Fuel Injector Rail

    Courtesy of GENERAL MOTORS CORP.
11. Install the fuel feed and return pipe retaining clip.
12. Install the fuel feed and return pipe retaining clip bolt.

    Tighten 

    Tighten the fuel feed and return pipe retaining clip bolt to 8 N.m (71 lb in).

    Fig 5: Installing Fuel Feed And Return Pipe Retaining Clip

    Courtesy of GENERAL MOTORS CORP.