Liberty, Wrangler, 1997-2005

Intake Manifold

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Removal & Installation



2.5L Engines
  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
     
    Air intake hose
     
    Accessory drive belt
     
    Power steering pump and brackets, if equipped
     
    Fuel line
     
    Accelerator cable
     
    Cruise control cable, if equipped
     
    Transmission cable, if equipped
     
    Throttle Position (TP) sensor connector
     
    Idle Air Control (IAC) valve connector
     
    Engine Coolant Temperature (ECT) sensor connector
     
    Intake Air Temperature (IAT) sensor connector
     
    Heated Oxygen (HO 2 ) sensor connector
     
    Fuel injector connectors
     
    Closed Crankcase Ventilation (CCV) system
     
    Manifold Absolute Pressure (MAP) sensor vacuum line
     
    Brake booster vacuum line
     
    Exhaust front pipe
     
    Intake manifold and discard the gaskets
     
    Exhaust manifold and discard the gaskets
     

  8.  

To install:

Click image to see an enlarged view

Fig. Manifold head torque sequence-2.5L engine

  1. Install or connect the following:

    New gasket over the locating dowels
     
    Exhaust manifold to the studs and tighten the nuts finger-tight
     

  2.  
  3. Install the intake manifold. Torque the fasteners in sequence as follows:
    1. Step 1: Bolt 1 to 30 ft. lbs. (41 Nm).
    2.  
    3. Step 2: Fasteners 2-7 to 23 ft. lbs. (31 Nm).
    4.  

  4.  
  5. Install or connect the following:

    Exhaust front pipe
     
    Brake booster vacuum line
     
    MAP sensor vacuum line
     
    CCV system
     
    Fuel injector connectors
     
    HO 2 sensor connector
     
    IAT sensor connector
     
    ECT sensor connector
     
    IAC valve connector
     
    TP sensor connector
     
    Transmission cable, if equipped
     
    Cruise control cable, if equipped
     
    Accelerator cable
     
    Fuel line
     
    Power steering pump and brackets, if equipped
     
    Accessory drive belt
     
    Air intake hose
     
    Negative battery cable
     

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

3.7L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Properly relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Air cleaner assembly
     
    Accelerator cable
     
    Cruise control cable
     
    Manifold Absolute Pressure (MAP) sensor connector
     
    Intake Air Temperature (IAT) sensor connector
     
    Throttle Position (TP) sensor connector
     
    Idle Air Control (IAC) valve connector
     
    Engine Coolant Temperature (ECT) sensor
     
    Positive Crankcase Ventilation (PCV) valve and hose
     
    Canister purge vacuum line
     
    Brake booster vacuum line
     
    Cruise control servo hose
     
    Accessory drive belt
     
    Alternator
     
    A/C compressor
     
    Engine ground straps
     
    Ignition coil towers
     
    Oil dipstick tube
     
    Fuel line
     
    Fuel supply manifold
     
    Throttle body and mounting bracket
     
    Cowl seal
     
    Right engine lifting stud
     
    Intake manifold. Remove the fasteners in reverse of the tightening sequence.
     

  8.  

To install:

Click image to see an enlarged view

Fig. Intake manifold torque sequence-3.7 and 4.7L engines

  1. Install or connect the following:

    Intake manifold using new gaskets. Torque the bolts, in sequence, to 105 inch lbs. (12 Nm).
     
    Right engine lifting stud
     
    Cowl seal
     
    Throttle body and mounting bracket
     
    Fuel supply manifold
     
    Fuel line
     
    Oil dipstick tube
     
    Ignition coil towers
     
    Engine ground straps
     
    A/C compressor
     
    Alternator
     
    Accessory drive belt
     
    Cruise control servo hose
     
    Brake booster vacuum line
     
    Canister purge vacuum line
     
    PCV valve and hose
     
    ECT sensor
     
    IAC valve connector
     
    TP sensor connector
     
    IAT sensor connector
     
    MAP sensor connector
     
    Cruise control cable
     
    Accelerator cable
     
    Air cleaner assembly
     
    Negative battery cable
     

  2.  
  3. Fill and bleed the cooling system.
  4.  
  5. Start the engine, check for leaks and repair if necessary.
  6.  

4.0L Engine

NOTE
The intake and engine exhaust manifolds on the 4.0L engine must be removed and installed together. The two manifolds use a common gasket at the cylinder head.

  1. Disconnect the battery negative cable.
  2.  
  3. Remove air cleaner inlet hose from the throttle body and air cleaner assembly.
  4.  
  5. Disconnect the accelerator cable, speed control cable (if equipped) and the transmission line pressure cable (if equipped) Remove these cables from the bracket.
  6.  
  7. Disconnect the following electrical connectors:

    Manifold Absolute Pressure (MAP) Sensor
     
    Idle Air Control (IAC) Motor
     
    Intake Manifold Air Temperature (IAT) Sensor
     
    Throttle Position Sensor (TPS)
     
    Oxygen Sensor Connector
     
    Fuel Injector Connectors
     

  8.  
  9. Secure the electrical harness out of the way.
  10.  
  11. Disconnect the power brake booster vacuum supply hose from the intake manifold.
  12.  
  13. Disconnect the CCV hose from the intake manifold.
  14.  
  15. Disconnect the HVAC vacuum supply hose from the intake manifold.
  16.  
  17. Disconnect canister purge vacuum supply form the intake manifold.
  18.  
  19. Perform the fuel pressure release procedure.
  20.  
  21. Disconnect fuel supply line from the fuel rail assembly.
  22.  
  23. Loosen the accessory drive belt. Slip the belt off of the power steering pulley.
  24.  
  25. Remove the power steering pump and bracket from the intake manifold and water pump and set aside.
  26.  
  27. Raise vehicle on hoist.
  28.  
  29. Disconnect the exhaust pipe from the exhaust manifold. Discard the seal.
  30.  
  31. Lower the vehicle.
  32.  
  33. Remove the intake manifold and exhaust manifold
  34.  

To install:

Click image to see an enlarged view

Fig. The installation of the intake manifold on the 4.0L engine

  1. Clean the mating surfaces of the cylinder head and the manifold(s) If the manifold is being replaced, ensure that all the fittings, etc. are transferred to the replacement manifold.
  2.  
  3. Install a new exhaust/intake manifold gasket over the alignment dowels on the cylinder head.
  4.  
  5. Position the engine exhaust manifold to the cylinder head. Install fastener No.3 and finger tighten at this time.
  6.  
  7. Install intake manifold on the cylinder head dowels.
  8.  
  9. Install washers and fasteners Nos. 1, 2, 4, 5, 8, 9, 10 and.
  10.  
  11. Install washers and fasteners Nos. 6 and 7.
  12.  
  13. Tighten the fasteners in sequence and to the specified torque.
  14.  
  15. Fasteners Nos. 1 through 5 - Tighten to 24 ft. lbs. (33 Nm) torque.
  16.  
  17. Fasteners Nos. 6 and 7 - Tighten to 23 ft. lbs. (31 Nm) torque.
  18.  
  19. Fasteners Nos. 8 through 11 - Tighten to 24 ft. lbs. (33 Nm) torque.
  20.  
  21. Install the power steering pump and bracket to the intake manifold and water pump. Torque the power steering pump/bracket to manifold bolts to 21 ft. lbs. (28 Nm) Torque the power steering pump bracket to water pump bolts to 35 ft. lbs. (47 Nm).
  22.  
  23. Install accessory drive belt and tighten to specification.
  24.  
  25. Before connecting the fuel line to the fuel rail, inspect the fuel line O-rings and replace them if necessary. Connect the fuel supply line to the fuel rail assembly.
  26.  
  27. Connect all sensor electrical connections on the intake manifold.

    MAP Sensor
     
    IAC Motor
     
    IAT Sensor
     
    TPS
     
    Oxygen Sensor Connector
     
    Fuel Injector Connectors
     

  28.  
  29. Connect the power brake booster and HVAC vacuum supply hoses.
  30.  
  31. Connect the canister purge vacuum supply hose to the manifold.
  32.  
  33. Install the throttle cable, cruise control cable (if equipped), and transmission line pressure (if equipped) cables into the bracket. Connect the cables to the throttle body.
  34.  
  35. Connect air inlet hose to the throttle body and air cleaner housing.
  36.  
  37. Raise vehicle on hoist.
  38.  
  39. Using a new seal, connect the exhaust pipe to the engine exhaust manifold. Tighten the bolts to 23 ft. lbs. (31 Nm) torque.
  40.  
  41. Lower the vehicle.
  42.  
  43. Connect the battery negative cable.
  44.  
  45. Start the engine and check for leaks.
  46.  

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

    Negative battery cable
     
    Air cleaner assembly
     
    Accessory drive belt
     
    Power steering pump and brackets, if equipped
     
    Fuel line
     
    Fuel injector connectors
     
    Fuel supply manifold and injectors
     
    Accelerator cable
     
    Cruise control cable, if equipped
     
    Transmission cable, if equipped
     
    Throttle Position (TP) sensor connector
     
    Idle Air Control (IAC) valve connector
     
    Engine Coolant Temperature (ECT) sensor connector
     
    Intake Air Temperature (IAT) sensor connector
     
    Heated Oxygen (HO 2 S) sensor connector
     
    Closed Crankcase Ventilation (CCV) system
     
    Manifold Absolute Pressure (MAP) sensor vacuum line
     
    Brake booster vacuum line
     
    Exhaust front pipe
     
    Intake and exhaust manifolds and discard the gaskets
     

  8.  

To install:

  1. Install or connect the following:

    New gasket over the locating dowels
     
    Exhaust manifold to the studs and tighten the nuts finger-tight

    Click image to see an enlarged view

    Fig. Manifold torque sequence-2002-04 4.0L engine

     

  2.  
  3. Install the intake manifold. Torque the fasteners in sequence as follows:
    1. Step 1: Fasteners 1-5 to 30 ft. lbs. (41 Nm).
    2.  
    3. Step 2: Fasteners 6 and 7 to 23 ft. lbs. (31 Nm).
    4.  
    5. Step 3: Fasteners 8-11 to 24 ft. lbs. (33 Nm)
    6.  

  4.  
  5. Install or connect the following:

    Exhaust front pipe
     
    Brake booster vacuum line
     
    MAP sensor vacuum line
     
    CCV system
     
    HO 2 S sensor connector
     
    IAT sensor connector
     
    ECT sensor connector
     
    IAC valve connector
     
    TP sensor connector
     
    Transmission cable, if equipped
     
    Cruise control cable, if equipped
     
    Accelerator cable
     
    Fuel supply manifold and injectors
     
    Fuel injector connectors
     
    Fuel line
     
    Power steering pump and brackets, if equipped
     
    Accessory drive belt
     
    Air cleaner assembly
     
    Negative battery cable
     

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

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Disconnect the battery negative cable.
  4.  
  5. Remove air cleaner inlet hose from the resonator assembly.
  6.  
  7. Remove the air cleaner assembly.
  8.  
  9. Remove the throttle cable, vehicle speed control cable (if equipped) and the transmission line pressure cable.
  10.  
  11. Disconnect the following electrical connections and secure their harness out of the way:

    Throttle Position Sensor
     
    Idle Air Control Motor
     
    Coolant Temperature Sensor (at thermostat housing)
     
    Intake Air Temperature Sensor
     
    Oxygen Sensor
     
    Crank Position Sensor
     
    Six Fuel Injector Connectors
     
    Manifold Absolute Pressure (MAP) Sensor.
     

  12.  
  13. Disconnect HVAC, and Brake Booster vacuum supply hoses at the intake manifold.
  14.  
  15. Perform the fuel pressure release procedure.
  16.  
  17. Disconnect and remove the fuel system supply line from the fuel rail assembly.
  18.  
  19. Remove the accessory drive belt.
  20.  
  21. Remove the power steering pump from the intake manifold and set aside.
  22.  
  23. Raise the vehicle.
  24.  
  25. Disconnect the exhaust pipes from the engine exhaust manifolds.
  26.  
  27. Lower the vehicle.
  28.  
  29. Remove the intake manifold and exhaust manifold bolts and manifolds.
  30.  

To install: