Lower Intake Manifold

CAUTION: This engine uses a sequential multiport fuel injection system. Injector connectors must be connected to their appropriate fuel injector or exhaust emissions and engine performance may be seriously affected.

REMOVAL
1. Disconnect the battery ground (negative) cable.
2. Remove the upper intake manifold.
3. Remove the left (front) valve rocker arm cover.
4. Remove the right (rear) valve rocker arm cover.
5. Remove the fuel feed and return pipe from the fuel injector rail. See Powertrain Management.
6. Remove the fuel injector rail. See Powertrain Management.
7. Remove the power steering pump from the front engine cover and reposition aside. See Steering and Suspension.
8. Disconnect the heater inlet pipe from the lower intake manifold.
9. Disconnect the upper radiator hose from the engine. See Cooling System.





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





12. Remove the lower intake manifold gaskets and seals.
13. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
14. Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
15. Remove all the loose RTV sealer.

INSTALLATION
1. Apply 8-12 mm (0.08-0.11 inch) bead of RTV Sealer, GM P/N 12345739 or equivalent, on each ridge where front and rear of the lower intake manifold contact the engine block (1).
2. Install the lower intake manifold gaskets.
3. Install the lower intake manifold.
4. Apply sealant, GM P/N 12345382 to the threads of the bolts.

CAUTION: An oil leak may result if the vertical bolts are not tightened before the diagonal bolts.

5. Hand tighten the vertical bolts.
6. Hand tighten the diagonal bolts.
a. Tighten the vertical bolts to 13 Nm (115 inch lbs.).
b. Tighten the diagonal bolts to 13 Nm (115 inch lbs.).
7. Connect the upper radiator hose to the engine. See Cooling System.
8. Connect the heater inlet pipe to the lower intake manifold.
9. Install the power steering pump to the front engine cover. See Steering and Suspension.
10. Install the fuel injector rail. See Powertrain Management.
11. Connect the fuel feed and return pipe to the fuel injector rail. See Powertrain Management.
12. Install the right (rear) valve rocker arm cover.
13. Install the left (front) valve rocker arm cover.
14. Install the upper intake manifold.
15. Connect the battery ground (negative) cable.