Intake Manifold Replacement Upper

1. Disconnect the battery negative cable assembly from the battery negative terminal. Refer to

   Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

   in General Information.
2. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.
3. Remove the air cleaner assembly and intake duct.
4. Remove the coolant reservoir. Refer to Coolant Reservoir Replacement in Engine Cooling.
5. Remove the wiring harness connectors and the brackets and move aside.



6. Remove the throttle cable and the bracket from the upper intake manifold.
7. Remove the cruise control cable (if equipped).
8. Remove the fuel lines from the intake to the rear of the intake manifold.
9. Remove the fuel line bracket at the rear of the lower intake manifold.
10. Remove the PCV hose at the upper intake manifold.
11. Remove the purge solenoid and bracket.
12. Remove the upper intake manifold bolts and studs. Mark the location of all studs for proper reassembly.
13. Remove the upper intake manifold.

1. Install the upper intake manifold gasket.
2. Install the upper intake manifold. Use care not to pinch the injector lines between the upper and lower intake manifolds.
3. Install the upper intake manifold bolts. Note the marks made at disassembly for proper stud location.
4. Tighten the bolts in two steps:

Tighten

1. Tighten the bolts on the first pass in sequence to 5 N·m (45 lb in).
2. Tighten the bolts on the final pass in sequence to 10 N·m (83 lb in).
5. Install the purge solenoid and bracket.
6. Install the PCV hose at the upper intake manifold.
7. Install the fuel lines from the intake to the rear of the intake manifold.
8. Install the fuel line bracket at the rear of the lower intake manifold.
9. Install the cruise control cable, if equipped.
10. Install the throttle cable and bracket.
11. Connect all wiring harness connectors.
12. Install the air cleaner assembly and intake duct.
13. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim.
14. Connect the battery negative cable assembly to the battery negative terminal.

Tighten
Tighten the bolt to 15 N·m (11 lb ft).

Intake Manifold Replacement Lower

1. Drain the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.
2. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.
3. Remove the air cleaner assembly and intake duct.
4. Remove the coolant reservoir. Refer to Coolalnt Reservoir Replacement in Engine Cooling.
5. Mark the relationship of the distributor housing and rotor for proper reassembly.
6. Remove the distributor. Refer to Distributor Removal Distributor Removal .
7. Remove the upper radiator hose at the thermostat housing.
8. Remove the heater hose at the lower intake manifold. Refer to Heater Hose Replacement in Engine Cooling.
9. Remove the EGR valve. Refer Exhaust Gas Recirculation Valve Replacement EGR Valve 4.3L,5.0L,5.7Lin Engine Controls.
10. Remove the coolant bypass hose.
11. Remove the fuel line bracket at the rear of the lower intake manifold.
12. Remove the wiring harness, electrical connectors, and brackets.
13. Remove the throttle cable and bracket at the throttle body.
14. Remove the cruise control cable (if equipped).
15. Remove the ignition coil and bracket. Refer to Ignition Coil Replacement in Engine Electrical.
16. Remove the left valve rocker cover. Refer to Valve Rocker Arm Cover Replacement Valve Rocker Arm Cover Replacement .
17. Remove the transmission oil level indicator tube.
18. Remove the EGR inlet tube, clamp, and bolt.
19. Remove the PCV valve and vacuum hoses.
20. Remove the air conditioning compressor and bracket. Refer to Compressor in Heater, Ventilation, and Air Conditioning:

•	Remove the rear A/C line, if equipped.

•	Loosen the A/C compressor mounting bracket and slide forward, do not remove.

21. Remove the generator rear bracket bolt (if needed). Refer to Generator Replacement in Engine Elecrical.



22. Remove the lower intake manifold bolts.
23. Remove the lower intake manifold.
24. Remove the old pieces of gasket from the gasket surfaces.
25. Remove excessive carbon buildup from inside the exhaust passages.
26. Remove the scale and deposits from the coolant passages.
27. Clean the EGR passage of excessive carbon deposits.
28. Inspect the manifold for cracks, broken flanges, and gasket surface damage.

Notice: Apply the proper amount of the sealant when assembling this component. Excessive use of the sealant can prohibit the component from sealing properly. A component that is not sealed properly can leak leading to extensive engine damage.

Important: Do not reuse the intake manifold gaskets.

1. Apply a 4.0 mm (0.157 in) patch of sealant to the cylinder head side of the intake manifold gasket at each end.
2. Install the gasket onto the cylinder head.
3. Use the gasket locator pins in order to properly seat the gasket on the cylinder head.



4. Apply a 5 mm (0.197 in) bead of sealant GM P/N 12346192 or the equivalent to the front block.



5. Apply a 5 mm (0.197 in) bead of sealant GM P/N 12346192 or the equivalent to the rear block.
6. Extend the sealer bead 13 mm (0.499 in) onto each gasket.
7. Apply the threadlocking sealant GM P/N 12345382 or equivalent to the threads of the lower intake mounting bolts.



8. Install the lower intake manifold onto the engine block.



9. Install the lower intake manifold bolts.

Tighten

1. Tighten the bolts first pass in sequence to 3 N·m (27 lb in).
2. Tighten the bolts second pass in sequence to 12 N·m (106 lb in).
3. Tighten the bolts final pass in sequence to 15 N·m (11 lb in).

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

10. Install the wiring harness connectors and brackets.
11. Install the upper radiator hose at the thermostat housing.
12. Install the heater hose at the lower intake manifold.
13. Install the coolant by pass hose.
14. Install the EGR valve.
15. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement Valve Rocker Arm Cover Replacement .
16. Install the fuel lines at the rear of the intake manifold.
17. Install the wiring harness and all electrical connectors and brackets.
18. Install the cruise control cable (if equipped).
19. Install the throttle cable and bracket to the throttle body.
20. Install the transmission oil level indicator tube.
21. Install the EGR inlet tube, clamp, and bolt.
22. Install the PCV valve and vacuum hoses.
23. Install the ignition coil and bracket. Refer to Ignition Coil Replacement in Engine Electrical.
24. Install the generator and the bracket bolt (if needed). Refer to Generator Replacement in Engine Electrical.
25. Install the air conditioning compressor and bracket. Refer to Compressor Replacement in Heater, Ventilation and Air Conditioning.
26. Install the rear A/C line, if equipped.
27. Install the distributor. Note the relationship of the distributor housing and rotor made at disassembly. Refer to Distributor Installation Distributor Installation .
28. Install the air cleaner assembly and intake duct.
29. Install the coolant reservoir. Refer to Coolant Reservoir Replacement in Engine Cooling.
30. Fill the cooling system with the proper quality and grade of coolant. Refer to Draining and Filling Cooling System in Engine Cooling.