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. With gaskets in place apply a small drop 8-10 mm (0.31-0.39 in) of RTV sealer GM P/N 12378479 (Canadian P/N 10953472) or equivalent to the four corners of the intake manifold to block joint (1).
2. Connect the two 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).
3. Install the lower intake manifold.
   NOTE: When replacing lower intake manifold gasket, a revised intake manifold gasket has been introduced by manufacturer. This new design gasket helps resolve issues related to intake manifold oil/coolant leaks. The gasket requires a revised torque specification and procedure in addition to the use of NEW revised intake manifold bolts. Please review TSB ENGINE OIL OR COOLANT LEAK (INSTALL NEW INTAKE MANIFOLD GASKET) for complete information.
   Fig 1: Installing Lower Intake Manifold & Identifying Sealant Application Locations

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

   Tighten See TSB For Revised Lower Intake Torque

   Fig 2: Lower Intake Manifold Bolt Tightening Sequence

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

   Tighten 

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

   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.

8. Install the fuel injector rail assembly.
   1. 8.1 Install the fuel injector O-rings using GM P/N 12345616, (Canadian P/N 993182) or the equivalent.
   2. 8.2 Install the injector nozzles into the lower intake manifold injector bores.
   3. 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 

   Tighten the fuel injector rail bolts to 10 N.m (89 INCH lbs).

   Fig 4: Installing Fuel Injection Rails

   Courtesy of GENERAL MOTORS CORP.
10. Install the fuel feed and return pipe retaining clip.
11. 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 INCH lbs).

    Fig 5: Installing Fuel Feed And Return Pipe Retaining Clip

    Courtesy of GENERAL MOTORS CORP.