Intake Manifold Replacement Upper

Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.

1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
2. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
3. Drain the engine coolant from the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.



4. Remove the throttle body air inlet duct. Refer to Air Cleaner Element Replacement in Engine Controls - 3.4L.



5. Remove the accelerator control and cruise control cables with bracket from the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls 3.4L.
6. Disconnect the wiring harness connectors from the Throttle Position (TP) sensor and the Idle Air Control (IAC) valve.
7. Disconnect the engine left side spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
8. Disconnect the engine left side spark plug wire harness attachment clip. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
9. Disconnect the throttle body heater hoses from the throttle body. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in HVAC Systems - Manual.



10. Disconnect the vacuum hoses from the evaporative emissions canister purge solenoid valve.



11. Remove the evaporative emissions canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.4L.



12. Remove the ignition coil bracket with the coils. Refer to Ignition Control Module Replacement in Engine Controls - 3.4L.



13. Disconnect the wiring harness from the Manifold Air Pressure (MAP) sensor.



14. Disconnect the vacuum hose from the Manifold Air Pressure (MAP) sensor and the upper intake manifold.



15. Disconnect and remove the emission control vacuum harness.
16. Disconnect the vacuum brake booster hose from the upper intake manifold. Refer to Vacuum Brake Booster Hose Replacement .
17. Disconnect the vacuum hose/pipe connections from the following:

•	The automatic transaxle vacuum modulator

•	The HVAC vacuum source fitting

•	The fuel pressure regulator

18. Remove the generator front brace. Refer to Generator Brace Replacement in Engine Electrical.
19. Remove the generator rear brace. Refer to Generator Brace Replacement in Engine Electrical.



20. Remove the Exhaust Gas Recirculation (EGR) valve. Refer to Exhaust Gas Recirculation Valve Replacement in Engine Controls - 3.4L.
21. Remove the Manifold Air Pressure (MAP) sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.4L.



22. Remove the upper intake manifold studs and bolts.



23. Remove the upper intake manifold.



24. If you are replacing the intake manifold, remove the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.4L.



25. Remove the upper intake manifold gasket.
26. Clean and inspect the upper intake manifold. Refer to Intake Manifold Cleaning and Inspection .

1. If removed, install the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.4L.



2. Install the upper intake manifold gasket.



3. Install the upper intake manifold.



4. Install the Manifold Air Pressure (MAP) sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.4L.
5. Install the upper intake manifold 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.

6. Install the upper intake manifold bolts.

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




7. Install the Exhaust Gas Recirculation (EGR) valve. Refer to Exhaust Gas Recirculation Valve Replacement in Engine Controls - 3.4L.
8. Install the generator front brace. Refer to Generator Brace Replacement in Engine Electrical.
9. Install the generator rear brace. Refer to Generator Brace Replacement in Engine Electrical.
10. Connect the vacuum hose/pipe connections to the following:

•	The automatic transaxle vacuum modulator

•	The HVAC vacuum source fitting

•	The fuel pressure regulator

11. Connect the vacuum brake booster hose to the upper intake manifold. Refer to Vacuum Brake Booster Hose Replacement .
12. Install the Manifold Air Pressure (MAP) sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.4L.



13. Install and connect the emission control vacuum harness.



14. Connect the vacuum hose to the Manifold Air Pressure (MAP) sensor and the upper intake manifold.



15. Connect the wiring harness to the Manifold Air Pressure (MAP) sensor.



16. Install the ignition coil bracket with the coils. Refer to Ignition Control Module Replacement in Engine Controls - 3.4L.



17. Install the evaporative emissions canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.4L.



18. Connect the vacuum hoses to the evaporative emissions canister purge solenoid valve.
19. Connect the throttle body heater hoses from the throttle body. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in HVAC Systems - Manual.
20. Connect the engine left side spark plug wire harness attachment clip. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
21. Connect the engine left side spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
22. Connect the wiring harness connectors to the Throttle Position (TP) sensor and the Idle Air Control (IAC) valve.



23. Install the accelerator control and cruise control cables with bracket to the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls 3.4L.



24. Install the throttle body air inlet duct. Refer to Air Cleaner Element Replacement in Engine Controls - 3.4L.
25. Fill the cooling system with engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
26. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
27. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

Intake Manifold Replacement Lower

Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.

1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
2. Remove the upper intake manifold. Refer to Intake Manifold Replacement .
3. Remove the engine left side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
4. Remove the engine right side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .



5. Disconnect the wiring harness from the Engine Coolant Temperature (ECT) sensor.




Important: Use masking tape or another appropriate method in order to identify each fuel injector wiring harness connector cylinder number.

6. Disconnect and remove the fuel injector, Manifold Air Pressure (MAP) and Engine Coolant Temperature (ECT) wiring harness.
7. Disconnect the fuel hoses from the fuel rail. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 3.4L.



8. Remove the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.4L.
9. Remove the power steering pump from the front engine cover and reposition aside. Refer to Power Steering Pump Replacement in Power Steering System.



10. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition aside. Refer to Heater Inlet Pipe Replacement in HVAC System - Manual.
11. Disconnect the inlet radiator hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.



12. Disconnect the thermostat bypass hose from the lower intake manifold pipe.



13. Remove the lower intake manifold bolts and discard the bolts.



14. Remove the lower intake manifold.
15. Loosen the valve rocker arms and remove the push rods. Refer to Valve Rocker Arm and Push Rod Replacement .



16. Remove the lower intake manifold gaskets and seals.
17. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
18. Clean and inspect the lower intake manifold. Refer to Intake Manifold Cleaning and Inspection .
19. Remove all the loose RTV sealer.



20. If you are replacing the lower intake manifold, remove the Engine Coolant Temperature (ECT) sensor.



21. If you are replacing the lower intake manifold, remove the water outlet bolts.
22. Remove the water outlet.



23. If you are replacing the lower intake manifold, remove the thermostat.

1. If removed, install the thermostat.



2. If removed, 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. If removed, install the Engine Coolant Temperature (ECT) sensor.

Tighten
Tighten the Engine Coolant Temperature (ECT) sensor to 23 N·m (17 lb ft).




5. Apply 8-12 mm (0.08-0.11 in) bead of RTV Sealer GM P/N 12346141 (Canadian P/N 89022195) 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 push rods and tighten the valve rocker arms. Refer to Valve Rocker Arm and Push Rod Replacement .



8. Install the lower intake manifold.
9. Install NEW intake manifold bolts.




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

10. Install the lower intake manifold bolts.
11. Hand tighten the vertical lower intake manifold bolts.
12. Hand tighten the diagonal lower intake manifold bolts.



13. Tighten the lower intake manifold bolts.

Tighten

1. Tighten the vertical lower intake manifold bolts (1) to 7 N·m (62 lb in).
2. Tighten the diagonal lower intake manifold bolts (2) to 7 N·m (62 lb in).
3. Tighten the vertical lower intake manifold bolts (1) to 13 N·m (115 lb in).
4. Tighten the diagonal lower intake manifold bolts (2) to 25 N·m (18 lb ft).



14. Connect the thermostat bypass hose to the lower intake manifold pipe.
15. Connect the inlet radiator hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.



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



18. Install the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.4L.
19. Connect the fuel hoses to the fuel rail. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 3.4L.




Important: The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.

20. Install and connect the fuel injector, Manifold Air Pressure (MAP) and Engine Coolant Temperature (ECT) wiring harness.



21. Disconnect the wiring harness from the Engine Coolant Temperature (ECT) sensor.
22. Install the engine right side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
23. Install the engine left side valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
24. Install the upper intake manifold. Refer to Intake Manifold Replacement .
25. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.