Intake Manifold Installation - Lower

WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.

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.

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.

Install the lower intake manifold gaskets.
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).
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).
Install the lower intake manifold.

Fig 1: Installing Lower Intake Manifold
Courtesy of GENERAL MOTORS CORP.

NOTE: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.
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.
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: Installing Lower Intake Manifold Bolts
Courtesy of GENERAL MOTORS CORP.
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 3: Installing Heater Inlet Pipe And Nut
Courtesy of GENERAL MOTORS CORP.

Important: Do not press on the fuel pressure regulator valve when installing the fuel injector rail assembly.
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. 6.3. 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).

Fig 4: Installing Fuel Injector Rail And Bolts
Courtesy of GENERAL MOTORS CORP.
Install the fuel feed and return pipe retaining clip.
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 And Bolt
Courtesy of GENERAL MOTORS CORP.