Infiniti Car 1998-05

Intake Manifold 1

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Removal & Installation



2.0L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Fuel lines, vacuum hoses and electrical connectors
     
    Throttle linkage
     
    Intake manifold supports from the front and rear
     
    Intake manifold collector. Loosen the bolts in the sequence illustrated.
     
    Injector tube assembly
     
    Power steering oil pump and the oil filter bracket
     
    Intake manifold-to-cylinder head bolts. Loosen the bolts in the sequence illustrated.
     
    Intake manifold and discard the gasket
     

  8.  


    Click image to see an enlarged view

    Fig. Intake manifold collector bolt loosening sequence-2.0L engine



    Click image to see an enlarged view

    Fig. Intake manifold bolt loosening sequence-2.0L engine


To install:



Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-2.0L engine



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-2.0L engine

  1. Be sure all mating surfaces are clean prior to installation.
  2.  
  3. Fit a new gasket and the manifold into place. Start the support bolts to hold the manifold in place.
  4.  
  5. Install or connect the following:

    Intake manifold bolts. Torque the bolts in sequence to 13-15 ft. lbs. (18-21 Nm). Torque the bolts in 2 steps, starting at the center and working towards the ends.
     
    Injector tube assembly. Torque the bolts first to 84-96 inch lbs. (9-11 Nm), then to 15-20 ft. lbs. (21-26 Nm).
     
    Power steering oil pump and the oil filter bracket
     
    Intake manifold collector using a new gasket. Torque the bolts in sequence to 13-15 ft. lbs. (18-21 Nm).
     
    Fuel lines, vacuum hoses, electrical connectors and the throttle linkage
     
    Negative battery cable
     

  6.  
  7. Fill and bleed the cooling system.
  8.  
  9. Start the vehicle, check for leaks and repair if necessary.
  10.  

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Fuel lines, vacuum hoses and electrical connectors
     
    Throttle linkage
     
    Intake manifold supports from the front and rear
     
    Intake manifold collector. Loosen the bolts in the sequence illustrated
     
    Injector tube assembly
     
    Power steering oil pump and the oil filter bracket
     
    Intake manifold-to-cylinder head bolts. Loosen the bolts in the sequence illustrated.
     
    Intake manifold and discard the gasket

    Click image to see an enlarged view

    Fig. Intake manifold collector bolt loosening sequence-2.0L engine



    Click image to see an enlarged view

    Fig. Intake manifold bolt loosening sequence-2.0L engine

     

  8.  

To install:

Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-2.0L engine



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-2.0L engine

  1. Be sure all mating surfaces are clean prior to installation.
  2.  
  3. Fit a new gasket and the manifold into place. Start the support bolts to hold the manifold in place.
  4.  
  5. Install or connect the following:

    Intake manifold bolts. Torque the bolts in sequence to 13-15 ft. lbs. (18-21 Nm). Torque the bolts in 2 steps, starting at the center and working towards the ends
     
    Injector tube assembly. Torque the bolts first to 84-96 inch lbs. (9-11 Nm), then to 15-20 ft. lbs. (21-26 Nm)
     
    Power steering oil pump and the oil filter bracket
     
    Intake manifold collector using a new gasket. Torque the bolts in sequence to 13-15 ft. lbs. (18-21 Nm)
     
    Fuel lines, vacuum hoses, electrical connectors and the throttle linkage
     
    Negative battery cable
     

  6.  
  7. Fill and bleed the cooling system.
  8.  
  9. Start the vehicle, check for leaks and repair if necessary.
  10.  

3.0L & 3.5L Engines
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Throttle body coolant hoses
     
    Electrical connectors from the Throttle Position (TP) sensor
     
    Hoses from the throttle body, the Exhaust Gas Recirculation (EGR) valve, intake manifold collector, Idle Air Control (IAC) valve, and the fuel pressure regulator
     
    Evaporative emissions (EVAP) canister purge hose and blow-by hose
     
    EGR guide tube
     
    Accelerator cable from the throttle body
     
    Intake manifold collector support brackets
     
    Right side electrical connectors from the ignition coils
     
    Electrical connector from the crank angle sensor and the power transistor, if necessary
     
    Intake manifold collector-to-intake manifold bolts/nuts and remove the intake manifold collector
     

  8.  
  9. Fuel injector assembly by removing or disconnecting the following:

    Electrical connectors from the fuel injectors
     
    Fuel lines from the fuel injector assembly
     
    Fuel rail-to-cylinder head bolts
     
    Fuel rail assembly from the engine
     
    Intake manifold bolts/nuts in the reverse sequence of the torque procedure
     

  10.  
  11. Remove the intake manifold from the engine and discard the gaskets
  12.  
  13. Clean all gasket mounting surfaces.
  14.  

To install:



Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-3.0L and 3.5L engine, except G35



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-3.0L and 3.5L engine, except G35

  1. Using new gaskets, install the intake manifold to the engine.
  2.  
  3. Tighten the bolts/nuts in sequence as follows:
    1. Step 1: Tighten nuts and bolts to 44-86 inch lbs. (5-10 Nm).
    2.  
    3. Step 2: Tighten nuts and bolts to 20-23 ft. lbs. (26-31 Nm).
    4.  
    5. Step 3: Repeat step 2 at least 5 times until all nuts and bolts have a final torque of 20-23 ft. lbs. (26-31 Nm).
    6.  

  4.  
  5. Install the fuel injector assembly by installing or connecting the following:

    Fuel rail assembly to the engine
     

  6.  
  7. Install the fuel rail-to-cylinder head bolts and torque the bolts to 15-20 ft. lbs. (21-26 Nm) in the following sequence:
    1. Step 1: Tighten bolts in sequence to 84-96 inch lbs. (9-10 Nm).
    2.  
    3. Step 2: Tighten the bolts in sequence to 15-20 ft. lbs. (21-26 Nm).
    4.  



    Fuel lines to the fuel injector assembly
     
    Electrical connectors to the fuel injectors
     


    Click image to see an enlarged view

    Fig. Tighten the fuel rail (tube) bolts in the sequence illustrated-3.0L and 3.5L engines, except G35

    Intake manifold collector using a new gasket, and torque the intake manifold collector-to-intake manifold bolts/nuts to 13-16 ft. lbs. (18-22 Nm) in the sequence illustrated
     
    Intake manifold collector supports. Torque the bolts to 14-18 ft. lbs. (20-25 Nm).
     
    Electrical connector to the crank angle sensor and the power transistor, if disconnected
     
    Electrical connectors to the ignition coils and torque the mounting bolts to 27-33 inch lbs. (3-4 Nm)
     
    Accelerator cable to the throttle body
     
    EGR guide tube. Torque the bolts to 15-20 ft. lbs. (21-26 Nm) in 2 progressive steps
     
    EVAP canister purge hose and blow-by hose
     
    Hoses to the throttle body, EGR valve, intake manifold collector, IAC valve, and the fuel pressure regulator
     
    Electrical connectors to the TP sensor
     
    Throttle body coolant hoses
     
    Negative battery cable
     

  8.  
  9. Fill and bleed the cooling system.
  10.  
  11. Start the vehicle, check for leaks and repair if necessary.
  12.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Engine cover
     
    Air cleaner and duct
     
    Electric throttle control actuator, loosening the bolts in a criss-cross pattern
     
    Fuel sub-tube mounting bolt to disconnect it from the rear of the lower intake manifold (collector)
     
    Vacuum hose and water hose from the intake manifold collector
     
    Evaporative emissions (EVAP) canister purge volume control solenoid valve bracket mounting bolt from the intake manifold collector
     
    Intake manifold collector (upper) bolts in the sequence shown, then remove the collector
     


    Click image to see an enlarged view

    Fig. Intake manifold collector (upper) bolt loosening sequence-G35 models

    Positive Crankcase Ventilation (PCV) hose between the intake manifold collector and right side rocker arm cover
     
    Intake manifold collector (lower) bolts in the reverse of the sequence shown
     
    Intake manifold collector (lower) cover, gaskets and lower manifold collector
     


    Click image to see an enlarged view

    Fig. Intake manifold collector (lower) bolt tightening sequence. Use the reverse sequence for bolt removal-G35 models



    Click image to see an enlarged view

    Fig. Exploded view of the upper and lower intake manifold collectors and tightening specifications-G35 models

    Fuel rail and injector assembly
     
    Intake manifold bolts and nuts, in the reverse of the installation sequence
     

  8.  
  9. Discard all gaskets and clean all gasket mounting surfaces.
  10.  


    Click image to see an enlarged view

    Fig. Intake manifold bolt tightening sequence. Use the reverse sequence when removing the bolts-G35 models


To install:

  1. Install the intake manifold, with new gaskets. Install the intake manifold nut and bolts, in sequence, and tighten as follows:
    1. Stud bolts, if removed: 7.3-8.7 ft. lbs. (9.8-11.8 Nm).
    2.  
    3. Step 1: 4-7 ft. lbs. (5-10 Nm).
    4.  
    5. Step 2: 20-23 ft. lbs. (26-31 Nm).
    6.  
    7. Step 3: 20-23 ft. lbs. (26-31 Nm).
    8.  

  2.  
  3. Install or connect the following:

    Fuel rail and injector assembly
     
    New gaskets, lower manifold collector, and collector cover, as shown. Tighten the bolts, in sequence to 13-15 ft. lbs. (17.7-21.6 Nm).
     


    Click image to see an enlarged view

    Fig. Exploded view of the intake manifold collector installation-G35 models

    Intake manifold collector (upper). Torque the bolts and nuts, in sequence, to the specifications shown in the illustration.
     

  4.  
  5. The remainder of installation is the reverse of the removal procedure.
  6.  
  7. Fill and bleed the cooling system.
  8.  
  9. Start the vehicle, check for leaks and repair if necessary.
  10.  


    Click image to see an enlarged view

    Fig. Intake manifold collector (upper) bolt tightening sequence-G35 models


3.0L Engine
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Release the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Throttle body coolant hoses
     
    Electrical connectors from the Throttle Position (TP) sensor
     
    Hoses from the throttle body, the Exhaust Gas Recirculation (EGR) valve, intake manifold collector, Idle Air Control (IAC) valve, and the fuel pressure regulator
     
    Evaporative emissions (EVAP)canister purge hose and blow-by hose
     
    EGR guide tube
     
    Accelerator cable from the throttle body
     
    Intake manifold collector support brackets
     
    Right side electrical connectors from the ignition coils
     
    Electrical connector from the crank angle sensor and the power transistor, if necessary
     
    Intake manifold collector-to-intake manifold bolts/nuts and remove the intake manifold collector
     

  8.  
  9. Fuel injector assembly by removing or disconnecting the following:

    Electrical connectors from the fuel injectors
     
    Fuel lines from the fuel injector assembly
     
    Fuel rail-to-cylinder head bolts
     
    Fuel rail assembly from the engine
     
    Intake manifold bolts/nuts in the reverse sequence of the torque procedure
     

  10.  
  11. Remove the intake manifold from the engine and discard the gaskets
  12.  
  13. Clean all gasket mounting surfaces.
  14.  

To install:

Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-3.0L engine



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-3.0L engine

  1. Using new gaskets, install the intake manifold to the engine.
  2.  
  3. Tighten the bolts/nuts in sequence as follows:
    1. Step 1: Tighten nuts and bolts to 36-84 inch lbs. (5-10 Nm).
    2.  
    3. Step 2: Tighten nuts and bolts to 20-23 ft. lbs. (26-31 Nm).
    4.  
    5. Step 3: Repeat step 2 at least 5 times until all nuts and bolts have a final torque of 20-23 ft. lbs. (26-31 Nm).
    6.  

  4.  
  5. Install the fuel injector assembly by installing or connecting the following:

    Fuel rail assembly to the engine
     

  6.  
  7. Install the fuel rail-to-cylinder head bolts and torque the bolts to 15-20 ft. lbs. (21-26 Nm) in the following sequence:
    1. Step 1: Tighten bolts in sequence to 84-96 inch lbs. (9-10 Nm).
    2.  
    3. Step 2: Tighten the bolts in sequence to 15-20 ft. lbs. (21-26 Nm).

      Fuel lines to the fuel injector assembly
       
      Electrical connectors to the fuel injectors

      Click image to see an enlarged view

      Fig. Tighten the fuel rail (tube) bolts in the sequence illustrated-3.0L engine

       

    4.  

  8.  
  9. Install or connect the following:

    Intake manifold collector using a new gasket, and torque the intake manifold collector-to-intake manifold bolts/nuts to 13-16 ft. lbs. (18-22 Nm) in the sequence illustrated
     
    Intake manifold collector supports. Torque the bolts to 14-18 ft. lbs. (20-25 Nm)
     
    Electrical connector to the crank angle sensor and the power transistor, if disconnected
     
    Electrical connectors to the ignition coils and torque the mounting bolts to 27-33 inch lbs. (3-4 Nm)
     
    Accelerator cable to the throttle body
     
    EGR guide tube. Torque the bolts to 15-20 ft. lbs. (21-26 Nm) in 2 progressive steps
     
    EVAP canister purge hose and blow-by hose
     
    Hoses to the throttle body, EGR valve, intake manifold collector, IAC valve, and the fuel pressure regulator
     
    Electrical connectors to the TP sensor
     
    Throttle body coolant hoses
     
    Negative battery cable
     

  10.  
  11. Fill and bleed the cooling system.
  12.  
  13. Start the vehicle, check for leaks and repair if necessary.
  14.  

4.1L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Intake manifold collector
     
    Exhaust Gas Recirculation (EGR) valve
     
    EGR temperature sensor
     
    Throttle body
     
    Fuel injectors and lift up the fuel rail assembly with the injectors. Do not disconnect the fuel hose.
     
    Intake manifold and discard the gaskets
     

  8.  

To install:



Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-4.1L engine



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-4.1L engine

  1. Clean the intake manifold and intake manifold collector mounting surfaces
  2.  
  3. Install or connect the following:

    Intake manifold using new gaskets. Torque the bolts in sequence to 13-17 ft. lbs. (18-21 Nm).
     
    Fuel tube assembly. Torque the bolts in sequence first to 84-96 inch lbs. (9-11 Nm), then to 15-20 ft. lbs. (21-26 Nm).
     
    Throttle body
     

  4.  
  5. Torque the throttle body bolts in the following steps:
    1. Step 1: bolts in sequence to 80-96 inch lbs. (9-11 Nm).
    2.  
    3. Step 2: Bolts in sequence to 13-16 ft. lbs. (18-22 Nm).
    4.  



    EGR temperature sensor
     
    EGR valve
     


    Click image to see an enlarged view

    Fig. Exploded view of the intake manifold assembly, related components and the throttle body torque sequence-4.1L engines

    Intake manifold collector using a new gasket. Torque the bolts in sequence to 13-16 ft. lbs. (18-22 Nm).
     
    Negative battery cable
     

  6.  
  7. Fill and bleed the cooling system.
  8.  
  9. Start the vehicle, check for leaks and repair if necessary.
  10.  


    Click image to see an enlarged view

    Fig. To prevent possible tube breakage, be sure to tighten the fuel tube mounting bolts according to the sequence shown


  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Intake manifold collector
     
    Exhaust Gas Recirculation (EGR) valve
     
    EGR temperature sensor
     
    Throttle body
     
    Fuel injectors and lift up the fuel rail assembly with the injectors. Do not disconnect the fuel hose.
     
    Intake manifold and discard the gaskets
     

  8.  

To install:

Click image to see an enlarged view

Fig. Lower intake manifold torque sequence-4.1L engine



Click image to see an enlarged view

Fig. Upper intake manifold torque sequence-4.1L engine

  1. Clean the intake manifold and intake manifold collector mounting surfaces
  2.  
  3. Install or connect the following:

    Intake manifold using new gaskets. Torque the bolts in sequence to 13-17 ft. lbs. (18-21 Nm).
     
    Fuel tube assembly. Torque the bolts in sequence first to 84-96 inch lbs. (9-11 Nm), then to 15-20 ft. lbs. (21-26 Nm).
     
    Throttle body. Torque the bolts in the following steps:
     

    1. Step 1: bolts in sequence to 80-96 inch lbs. (9-11 Nm).
    2.  
    3. Step 2: Bolts in sequence to 13-16 ft. lbs. (18-22 Nm).
    4.  

  4.  
  5. Install or connect the following:

    EGR temperature sensor
     
    EGR valve

    Click image to see an enlarged view

    Fig. Exploded view of the intake manifold assembly, related components and the throttle body torque sequence-4.1L engines

     
    Intake manifold collector using a new gasket. Torque the bolts in sequence to 13-16 ft. lbs. (18-22 Nm).
     
    Negative battery cable
     

  6.  
  7. Fill and bleed the cooling system.
  8.  
  9. Start the vehicle, check for leaks and repair if necessary.

    Click image to see an enlarged view

    Fig. To prevent possible tube breakage, be sure to tighten the fuel tube mounting bolts according to the sequence shown

  10.  

 
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