Intake Manifold Replacement - Lower
Intake Manifold Replacement-Lower
Removal Procedure
1. Disconnect the battery ground (negative) cable.
2. Remove the upper intake manifold.
3. Remove the left valve rocker arm cover.
4. Remove the right valve rocker arm cover.
5. Disconnect the Engine Coolant Temperature (ECT) wiring harness.
6. Disconnect and remove the fuel injector and Manifold Air Pressure (MAP) wiring harness.
7. Remove the fuel pipe clip bolt.
8. Remove the fuel pipe clip.
9. Disconnect the fuel feed pipe from the fuel injector rail.
10. Disconnect the fuel return pipe from the fuel injector rail.
11. Remove the fuel injector rail.
12. Remove the power steering pump from the front engine cover and reposition.
13. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition.
14. Disconnect the radiator inlet hose from the engine.
15. Disconnect the thermostat bypass hose from the thermostat bypass pipe and lower intake manifold pipe.
16. Remove the lower intake manifold bolts.
17. Remove the lower intake manifold.
18. Remove the valve rocker arms and pushrods.
19. Remove the lower intake manifold gaskets and seals.
20. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
21. Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
22. Remove all the loose RTV sealer.
23. Remove the Engine Coolant Temperature (ECT) sensor.
24. Remove the water outlet bolts.
25. Remove the water outlet.
26. Remove the thermostat.
Installation Procedure
1. Install the thermostat.
2. Install the water outlet.
Notice: Refer to Fastener Notice in Service Precautions.
3. Install the water outlet bolts.
^ Tighten the water outlet bolts to 25 Nm (18 ft. lbs.).
4. Install the Engine Coolant Temperature (ECT) sensor.
^ Tighten the Engine Coolant Temperature (ECT) sensor to 23 Nm (17 ft. lbs.).
Note: Refer to TSB# 03-06-01-010B (10/24/2003) for updated information about a new intake manifold gasket and installation procedure.
5. 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).
6. Install the lower intake manifold gaskets.
7. Install the valve rocker arms and pushrods.
8. Install the lower intake manifold.
9. Apply sealant, GM P/N 12345382 to the threads of the bolts.
Notice: An oil leak may result if the vertical bolts are not tightened before the diagonal bolts.
10. Hand tighten the vertical lower intake manifold bolts.
11. Hand tighten the diagonal lower intake
12. Install NEW lower intake manifold bolts.
The torque specification is a 2-step process; tighten the vertical lower intake manifold bolts (the four middle ones) to 7 Nm (62 lb in). Tighten the diagonal lower intake manifold bolts (two on each end) to 7 Nm (62 lb in).Tighten the vertical lower intake manifold bolts (the four middle ones) to 13 Nm (115 lb in). Tighten the diagonal lower intake manifold bolts (two on each end) to 25 Nm (18 lb ft).
13. Connect the thermostat bypass hose to the thermostat bypass pipe and lower intake manifold pipe.
14. Connect the radiator inlet hose to the engine.
15. Connect the heater inlet pipe and heater hose to the lower intake manifold.
16. Install the power steering pump to the front engine cover.
17. Install the fuel injector rail.
18. Connect the fuel return pipe to the fuel injector rail.
19. Connect the fuel feed pipe to the fuel injector rail.
20. Install the fuel pipe clip.
21. Install the fuel pipe clip bolt.
^ Tighten the fuel pipe clip bolt to 8 Nm (71 inch lbs.).
22. Install and connect the fuel injector and Manifold Air Pressure (MAP) wiring harness.
23. Connect the Engine Coolant Temperature (ECT) wiring harness.
24. Install the right valve rocker arm cover.
25. Install the left valve rocker arm cover.
26. Install the upper intake manifold.
27. Connect the battery ground (negative) cable.