Intake Manifold Replacement Upper

Important: This engine uses a sequential multiport fuel injection system. Connect the injector wiring harness connectors to their appropriate fuel injector or exhaust emissions and engine performance may be seriously affected. For the correct injector wiring harness connector-to-fuel injector connection procedure, refer to Engine Controls - 3.0L (L46).

1. Disconnect the battery ground (negative) cable. Refer to Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
2. Remove the throttle body assembly and the accelerator controls cable bracket. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.0L (L46).
3. Disconnect the left hand spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
4. Disconnect the wiring harness attachment clips.

•	Camshaft position (CMP) sensor wiring harness.

•	Left hand spark plug wire harness.

•	Engine wiring harness.

5. Remove the ignition coil bracket with the coils, the purge solenoid and the vacuum canister solenoid. Refer to Ignition Control Module Replacement in Engine Controls - 3.0L (L46).



6. Disconnect the vacuum hose at the manifold air pressure (MAP) sensor and upper intake manifold.
7. Remove the manifold air pressure (MAP) sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.0L (L46).



8. Disconnect the emission control vacuum harness.
9. Disconnect the vacuum hose connections from the upper intake manifold.

•	Vacuum booster hose

•	Heater and air conditioning vacuum source hose

•	Fuel pressure regulator

10. Remove the generator brace. Refer to Generator Brace Replacement in Engine Electrical.



11. Remove the exhaust gas recirculation (EGR) valve and pipe. Refer to EGR Valve Replacement in Engine Controls 3.0L (L46).



12. Remove the upper intake manifold bolts and studs.
13. Remove the upper intake manifold.



14. Remove the upper intake manifold gaskets.
15. Clean the seal surfaces on the manifold with degreaser.

1. Install the upper intake manifold gaskets.
2. Install the upper intake manifold.
3. Loosely install the upper intake manifold bolts and studs.

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.

4. Install the upper intake manifold bolts and studs.

Tighten
Tighten the upper intake manifold bolts and studs to 25 N·m (18 lb ft).




5. Install the exhaust gas recirculation (EGR) valve. Refer to EGR Valve Replacement in Engine Controls 3.0L (L46).
6. Install the generator brace. Refer to Generator Brace Replacement in Engine Electrical.
7. Connect the vacuum hose connections to the upper intake manifold.

•	Vacuum booster hose

•	Heater and air conditioning vacuum source hose

•	Fuel pressure regulator




8. Connect the emission control vacuum harness.
9. Install the manifold air pressure (MAP) sensor and bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls 3.0L (L46).



10. Connect the vacuum hose at the manifold air pressure (MAP) sensor and the upper intake manifold.
11. Install the ignition coil bracket with the coils, the purge solenoid and the vacuum canister solenoid. Refer to Ignition Control Module Replacement in Engine Controls 3.0L (L46).
12. Connect the wiring harness attachment clips.

•	Camshaft position (CMP) sensor wiring harness

•	Left (front) spark plug wire harness

•	Engine wiring harness

13. Connect the left hand spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
14. Install the throttle body assembly and the accelerator controls cable bracket. Refer to Throttle Body Assembly Replacement in Engine Control 3.0L (L46).
15. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

Intake Manifold Replacement Lower

Important: This engine uses a sequential multiport fuel injection system. Injector wiring harness connectors must be connected to their appropriate fuel injector or exhaust emissions and engine performance may be seriously affected. For the correct injector wiring harness connector-to-fuel injector connection procedure, refer to Engine Controls - 3.0L.

1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
2. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Remove the upper intake manifold. Refer to Intake Manifold Replacement .
4. Remove the generator. Refer to Generator Replacement in Engine Electrical.
5. Remove the left hand valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
6. Remove the right hand valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .



7. Disconnect the engine coolant temperature (ECT) wiring harness Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.0L.



8. Disconnect and remove the fuel injector wiring harness. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.
9. Disconnect and remove the manifold air pressure (MAP) wiring harness. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.0L.



10. Remove the fuel pipe clip bolt.



11. Remove the fuel pipe clip.



12. Disconnect the fuel feed pipe from the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



13. Disconnect the fuel return pipe from the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



14. Remove the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.
15. Remove the power steering pump from the front engine cover and reposition aside. Refer to Power Steering Pump Replacement in Power Steering.



16. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition for access. Refer to Heater Inlet Pipe Replacement in HVAC.
17. Disconnect the radiator inlet hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.



18. Disconnect the thermostat bypass hose from the thermostat bypass pipe and lower intake manifold pipe.



19. Remove the lower intake manifold bolts.
20. Remove the lower intake manifold.



21. Remove the lower intake manifold gaskets and seals.
22. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
23. Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
24. Remove all the loose RTV sealer.



25. Remove the engine coolant temperature (ECT) sensor. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.0L.



26. Remove the water outlet bolts.
27. Remove the water outlet.



28. Remove the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

1. Install the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.



2. Install the water outlet.

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.

3. Install the water outlet bolts.

Tighten
Tighten the water outlet bolts to 25 N·m (18 lb ft).




4. Install the engine coolant temperature (ECT) sensor. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.0L.



5. Apply 8-12 mm (0.08-0.11 in) bead of RTV Sealer, 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 lower intake manifold.
8. 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.

9. Hand tighten the vertical lower intake manifold bolts.
10. Hand tighten the diagonal lower intake manifold bolts.



11. Install the lower intake manifold bolts.

Tighten

1. Tighten the vertical lower intake manifold bolts (1) to 13 N·m (115 lb in).
2. Tighten the diagonal lower intake manifold bolts (2) to 13 N·m (115 lb in).



12. Connect the thermostat bypass hose to the thermostat bypass pipe and lower intake manifold pipe.
13. Connect the radiator inlet hose to the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.



14. Connect the heater inlet pipe and heater hose to the lower intake manifold. Refer to Heater Inlet Pipe Replacement in HVAC.
15. Install the power steering pump to the front engine cover. Refer to Power Steering Pump Replacement in Power Steering.



16. Install the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



17. Connect the fuel return pipe to the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



18. Connect the fuel feed pipe to the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



19. Install the fuel pipe clip.



20. Install the fuel pipe clip bolt.

Tighten
Tighten the fuel pipe clip bolt to 8 N·m (71 lb in).




21. Install and connect the fuel injector wiring harness. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.
22. Install and connect the manifold air pressure (MAP) wiring harness. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.0L.



23. Connect the engine coolant temperature (ECT) wiring harness. Refer to Engine Coolant Temperature Sensor Replacement in Engine Controls - 3.0L.
24. Install the right hand valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
25. Install the left hand valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
26. Install the Generator. Refer to Generator Replacement in Engine Electrical.
27. Install the upper intake manifold. Refer to Intake Manifold Replacement .
28. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
29. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.