Intake Manifold Replacement - Lower

Intake Manifold Replacement - Lower
Removal Procedure





1. Remove the upper intake manifold.
2. Remove the valve rocker covers.





3. Remove the fuel rail with injectors and position aside.
4. Disconnect ECT.
5. Remove the power steering mounting bolts. Position the pump aside.





6. Remove the inlet cooling pipe from the coolant outlet housing.
7. Remove the heater by-pass at the coolant pump and the cylinder head.
8. Remove the radiator hose from thermostat housing.





9. Important: Retain the washers in the same orientation on the center bolts.

Remove the lower intake manifold bolts.
10. Remove the lower intake manifold.





11. Loosen the rocker arms.





12. Important: Keep the pushrods in order. The pushrods must be installed in the original position.

Remove the pushrods.





13. Remove the intake gasket.
14. Inspect the flatness of the inlet flanges.
15. If replacing intake remove the following components:
^ ECT
^ Thermostat housing
^ Thermostat

Installation Procedure





1. 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 intake manifold gasket.





2. Important: The intake valve pushrods measure 146.0 mm (5.75 inch) in length.

The exhaust valve pushrods measure 152.5 mm (6.0 inch) in length.
Install the pushrods.
1. Install the pushrods in their original location.
2. Coat the ends of the pushrods with prelube GM P/N 1052356, or the equivalent.
3. Intake pushrods are 144 mm (5.75 inch).
4. Exhaust pushrods are 152.5 mm (6.0 inch).
5. Ensure that the pushrods seat in the lifter.

3. Notice: Refer to Fastener Notice in Service Precautions.

Install the rocker arm bolts.
Tighten the bolts to 32 Nm (24 ft. lbs.).





4. 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.

With gaskets in place apply a small drop 8 - 10 mm (0.31 - 0.39 inch) of RTV sealer GM P/N 12346141 (Canadian P/N 10953433) or equivalent to the 4 corners of the intake manifold to block joint (1).
5. Connect the 2 small drops with a bead of RTV sealer that is between 8 -10 mm (0.31 - 0.39 inch) wide and 3.0 - 5.0 mm (0.12 - 0.20 inch) thick (2).
6. Install the lower intake manifold.





7. Important: All lower intake manifold bolts need to be cleaned, free of any foreign material, and reused only if new bolts are unavailable. Use GM P/N 12345382 (Canadian P/N 10953489) or equivalent and apply to the old intake manifold bolt threads.

Important: Manufacturer recommends the center bolts be fully torqued before the diagonal bolts to assure proper seal ability.

Important: Lower intake manifold bolts in location 6 and 7 should be torqued to specification using a crows foot type tool.

Notice: Refer to Fastener Notice in Service Precaution.

Install the lower intake manifold bolts.
1. Tighten the lower intake manifold bolts in sequence to 7 Nm (62 inch lbs.) on the first pass.
2. Tighten the lower intake manifold bolts (1, 2, 3, 4) in sequence to 13 Nm (115 inch lbs.) on the final pass.
3. Tighten the lower intake manifold bolts (5, 6, 7, 8) in sequence to 25 Nm (18 ft. lbs.) on the final pass.
8. Install the thermostat housing.
9. Install the radiator hose to the thermostat housing.





10. Install the heater inlet pipe to the thermostat housing.
11. Install the heater inlet pipe nut.
Tighten the heater inlet nut to 25 Nm (18 ft. lbs.).





12. Important: Do not use the fuel injector O-ring seals twice. Install NEW fuel injector O-ring seals during assembly.

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

Install the fuel injector rail assembly.
1. Install the fuel injector O-rings using GM P/N 12345616, (Canadian P/N 993182) or equivalent.
2. Install the injector nozzles into the lower intake manifold injector bores.
3. Press on the injector rail using the palms of both hands until the injectors are fully seated.
13. Install the fuel injector rail bolts.
Tighten the fuel injector rail bolts to 10 Nm (89 inch lbs.).





14. Install the fuel feed and return pipe retaining clip.
15. Install the fuel feed and return pipe retaining clip bolt.
Tighten the fuel feed and return pipe retaining clip bolt to 8 Nm (71 inch lbs.).





16. Install the upper intake manifold.
17. Install the valve rocker covers.