Intake Manifold: Service and Repair
Intake Manifold Installation:
REMOVE OR DISCONNECT
1. Relieve fuel system pressure.
2. Top half of the air cleaner assembly and throttle body duct.
3. Drain and recover cooling system.
4. EGR pipe from exhaust manifold.
5. Serpentine belt.
6. Brake vacuum pipe at plenum.
7. Power steering lines at generator bracket.
8. Generator.
9. Secondary ignition wires from spark plugs and harness at plenum.
10. Electronic ignition coil and module assembly and the EVAP canister purge solenoid at the same time.
11. Upper engine wiring harness connectors:
^ Throttle Position (TP) sensor.
^ Idle Air Control (IAC).
^ Injector harness.
^ Engine Coolant Temperature (ECT) sensor.
^ Manifold Absolute Pressure (MAP) sensor.
^ Camshaft Position (CMP) sensor.
12. Vacuum lines.
^ Vacuum Modulator.
^ Fuel Pressure Regulator.
^ Positive Crankcase Ventilation (PCV).
13. MAP sensor from upper intake manifold.
14. Upper intake manifold.
15. Fuel lines at fuel rail and remove from bracket.
16. Install engine support fixture, J 28467-A.
17. Right engine mount.
18. Power steering mounting bolts (support pump aside).
19. Coolant inlet pipe from coolant outlet housing.
20. Coolant by-pass at coolant pump and cylinder head.
21. Radiator hose at coolant outlet housing.
22. Coolant outlet housing.
23. Both valve rocker cover.
24. Lower intake manifold bolts.
IMPORTANT
^ Retain washers in same orientation on center bolts.
25. Loosen rocker arms.
26. Pushrods.
IMPORTANT
^ Place pushrods in order so they can be installed in their original position.
27. Intake gasket.
INSPECT
^ Flatness of inlet flanges.
CLEAN
^ Gasket material from mating surfaces.
^ Excess RTV sealant from front and rear ridges of cylinder block.
^ Sealing surfaces with degreaser.
INSTALL OR CONNECT
1. Place a 2-3 mm bead of GM RTV sealer P/N 1052917 or equivalent on each ridge where the front and rear of the intake manifold contact the block.
2. Intake manifold gasket.
3. Pushrods.
^ Install pushrods in their original location.
^ Coat the ends of the pushrods with prelube GM P/N 1052356.
^ Intake pushrods are marked red and are 5-3/4 inches long.
^ Exhaust pushrods are marked blue and are 6 inches long.
^ Make sure pushrods seat in lifter.
4. Rocker arm nuts. Tighten rocker arm nuts to 24 Nm (18 lb. ft.).
5. Lower intake manifold.
6. Lower intake manifold bolts. Tighten the vertical bolts first to 13 Nm (115 lb. in.). Tighten the diagonal bolts second to 13 Nm (115 lb. in.).
^ Apply sealant GM P/N 12345739 to threads of bolts.
7. Front valve rocker cover.
8. Coolant outlet housing.
9. Radiator hose to thermostat housing.
10. Coolant inlet pipe to thermostat housing.
11. Coolant by-pass pipe at coolant pump and cylinder head.
12. Power steering pump.
13. Loosely install serpentine belt due to trap design.
14. Right engine mount.
15. Remove engine support fixture, J 28467-A
16. Fuel lines to fuel rail and bracket.
17. Upper intake manifold. Tighten bolts to 25 Nm (18 lb. ft.).
18. MAP sensor.
19. Connect vacuum lines.
^ Vacuum Modulator.
^ Fuel Pressure Regulator.
^ PCV.
20. Engine wiring connectors.
^ TP sensor.
^ IAC.
^ Injector harness.
^ ECT sensor.
^ MAP sensor.
^ CMP sensor.
21. EVAP canister purge solenoid and Electronic ignition coil and module assembly.
22. Generator.
23. Power steering line at generator bracket.
24. Serpentine belt.
25. Secondary wires to spark plugs.
26. EGR pipe to exhaust manifold.
27. Throttle control and cruise control cables to the throttle body.
28. Air intake duct and top half of the air cleaner assembly.
29. Brake vacuum pipe.
30. Cables to throttle body.
31. Fill cooling system.
32. Negative battery cable.
INSPECT
^ Proper fluid levels.
^ Leaks.