Lexus GS, SC 1998-06

Intake Manifold

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Removal & Installation



1uz-FE & 3uz-FE Engines


Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-4.0L (1UZ-FE) and 4.3L (3UZ-FE) Engines

  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. Remove or disconnect the following:

    Negative battery cable
     
    Coolant
     
    Accelerator cable
     
    Throttle and accelerator pedal position electrical connectors
     
    Throttle motor electrical connector
     
    Vacuum Switching Valve (VSV) electrical connectors
     
    Injector electrical connectors
     
    Noise filter electrical connector
     
    Brake booster vacuum hose from the intake manifold
     
    Positive Crankcase Ventilation (PCV) hose from the left-hand valve cover
     
    Evaporative Emission (EVAP) hoses and label for installation
     
    Power steering air hose from the intake manifold
     
    Coolant hoses from the throttle body
     
    2 EVAP-to-intake manifold mounting bolts
     
    Accelerator cable bracket
     
    3 V-bank cover brackets
     
    EVAP VSV
     
    Fuel supply and return lines
     
    6 bolts and 4 nuts, then the intake manifold assembly
     

  6.  
  7. Clean the gasket mating surfaces of old gasket and sealant.
  8.  

To install:

  1. Install or connect the following:

    2 intake manifold gaskets on the cylinder heads with the white painted mark facing upward.
     
    Intake manifold assembly and uniformly, tighten the mounting bolts to 13 ft. lbs. (18 Nm).
     

  2.  
  3. The remaining steps of the installation procedure are the reverse of the removal, while keeping in mind the following items:

    Tighten the V-bank cover brackets to 66 inch lbs. (8 Nm).
     
    Tighten the accelerator cable bracket mounting bolts to 13 ft. lbs. (18 Nm).
     
    Tighten the EVAP VSV to 13 ft. lbs. (18 Nm).
     
    All remaining components.
     
    Coolant
     
    Negative battery cable
     

  4.  

1uz-FE Engine


Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-4.0L (1UZ-FE) and 4.3L (3UZ-FE) Engines

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

    Negative battery cable
     
    Coolant
     
    Accelerator cable
     
    Throttle and accelerator pedal position electrical connectors
     
    Throttle motor electrical connector
     
    Vacuum Switching Valve (VSV) electrical connectors
     
    Injector electrical connectors
     
    Noise filter electrical connector
     
    Brake booster vacuum hose from the intake manifold
     
    Positive Crankcase Ventilation (PCV) hose from the left-hand valve cover
     
    Evaporative Emission (EVAP) hoses and label for installation
     
    Power steering air hose from the intake manifold
     
    Coolant hoses from the throttle body
     
    2 EVAP-to-intake manifold mounting bolts
     
    Accelerator cable bracket
     
    3 V-bank cover brackets
     
    EVAP VSV
     
    Fuel supply and return lines
     
    6 bolts and 4 nuts, then the intake manifold assembly
     

  6.  
  7. Clean the gasket mating surfaces of old gasket and sealant.
  8.  

To install:

  1. Install or connect the following:

    2 intake manifold gaskets on the cylinder heads with the white painted mark facing upward.
     
    Intake manifold assembly and uniformly, tighten the mounting bolts to 13 ft. lbs. (18 Nm).
     

  2.  
  3. The remaining steps of the installation procedure are the reverse of the removal, while keeping in mind the following items:

    Tighten the V-bank cover brackets to 66 inch lbs. (8 Nm).
     
    Tighten the accelerator cable bracket mounting bolts to 13 ft. lbs. (18 Nm).
     
    Tighten the EVAP VSV to 13 ft. lbs. (18 Nm).
     
    All remaining components.
     
    Coolant
     
    Negative battery cable
     

  4.  

2jz-GE Engine


Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-3.0L (2JZ-GE) engine

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Coolant
     
    Spark plug wires at the spark plugs
     
    Spark plugs
     
    Distributor with the spark plug leads attached.
     
    Radiator
     
    Water pump pulley
     
    Timing belt
     
    No. 2 front exhaust pipe
     
    2 Oxygen (O 2 ) sensor leads
     
    4 nuts, and the manifold heat shield
     
    Exhaust manifolds.
     
    Water bypass outlet and the No. 1 bypass pipe. Remove the 3 O-rings.
     
    Water outlet
     
    No. 1 bypass hose
     
    Vacuum Control Valve (VCV) set and the No. 2 vacuum pipe
     
    Fuel return hose from the oil dipstick guide, remove the mounting bolt and pull the guide and dipstick from the pan. Plug the hole.
     
    Air intake chamber
     
    Fuel delivery pipe, then pull out the injectors.
     
    No. 1 and 2 fuel pipes
     
    Engine harness from the intake manifold
     
    Intake manifold stay
     
    Loosen the 6 bolts and 2 nuts, then lift out the intake manifold.
     

  4.  

To install:

  1. Install or connect the following:

    Install the intake manifold, with a new gasket, and tighten the bolts and nuts to 15 ft. lbs. (21 Nm).
     
    Mounting stay and tighten the bolts to 29 ft. lbs. (39 Nm).
     
    Engine harness to the manifold
     
    2 fuel pipes and tighten the bolts to 78 inch lbs. (9 Nm)
     
    Delivery pipe and injectors. Tighten the pipe bolts to 15 ft. lbs. (21 Nm).
     
    Air intake chamber and tighten it to 15 ft. lbs. (21 Nm).
     
    2 stays and tighten them to 13 ft. lbs. (18 Nm); The No. 1 stay is marked with an F and the No. 2 stay is marked with an R .
     
    The oil dipstick and guide, using a new O-ring
     
    VCV set and the vacuum pipe. Tighten the set mounting bolts to 15 ft. lbs. (21 Nm).
     
    Water bypass outlet and the pipe, tighten the bolts to 78 inch lbs. (9 Nm).
     
    Exhaust manifolds. Tighten the bolts to 29 ft. lbs. (39 Nm).
     
    Heat shield and tighten it to 13 ft. lbs. (18 Nm).
     
    No. 2 front pipe
     
    Timing belt
     
    Radiator and water pump pulley
     
    Distributor and spark plugs
     
    Plug wires to the plugs
     
    Coolant
     
    Negative battery cable
     

  2.  



Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-3.0L (2JZ-GE) engine

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Coolant
     
    Spark plug wires at the spark plugs
     
    Spark plugs
     
    Radiator
     
    Water pump pulley
     
    Timing belt
     
    No. 2 front exhaust pipe
     
    2 Oxygen (O 2 ) sensor leads
     
    4 nuts, and the manifold heat shield
     
    Exhaust manifolds
     
    Water bypass outlet and the No. 1 bypass pipe. Remove the 3 O-rings.
     
    Water outlet
     
    No. 1 bypass hose
     
    Vacuum Control Valve (VCV) set and the No. 2 vacuum pipe
     
    Fuel return hose from the oil dipstick guide; remove the mounting bolt and pull the guide and dipstick from the pan. Plug the hole.
     
    Air intake chamber
     
    Fuel delivery pipe, then pull out the injectors
     
    No. 1 and 2 fuel pipes
     
    Engine harness from the intake manifold
     
    Intake manifold stay
     
    Loosen the 6 bolts and 2 nuts, then lift out the intake manifold
     

  4.  

To install:

  1. Install or connect the following:

    Install the intake manifold, with a new gasket, and tighten the bolts and nuts to 21 ft. lbs. (28 Nm)
     
    Mounting stay and tighten the bolts to 29 ft. lbs. (39 Nm)
     
    Engine harness to the manifold
     
    2 fuel pipes and tighten the bolts to 78 inch lbs. (9 Nm)
     
    Delivery pipe and injectors. Tighten the pipe bolts to 15 ft. lbs. (21 Nm).
     
    Air intake chamber and tighten it to 15 ft. lbs. (21 Nm)
     
    2 stays and tighten them to 13 ft. lbs. (18 Nm); The No. 1 stay is marked with an F and the No. 2 stay is marked with an R .
     
    The oil dipstick and guide, using a new O-ring
     
    VCV set and the vacuum pipe. Tighten the set mounting bolts to 15 ft. lbs. (21 Nm).
     
    Water bypass outlet and the pipe, tighten the bolts to 78 inch lbs. (9 Nm)
     
    Exhaust manifolds. Tighten the bolts to 30 ft. lbs. (40 Nm).
     
    Heat shield and tighten it to 13 ft. lbs. (18 Nm)
     
    No. 2 front pipe
     
    Timing belt
     
    Radiator and water pump pulley
     
    Plug wires to the plugs
     
    Coolant
     
    Negative battery cable
     

  2.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Mark each wire, connector or hose, as it is removed, for proper reinstallation reference.



    Negative battery cable
     
    Engine under cover
     
    Engine coolant
     
    Engine cover
     
    Air cleaner assembly
     
    Throttle body assembly
     
    Water bypass pipe running through intake manifold
     
    Engine and transmission dipsticks and tubes
     
    Air intake chamber
     
    Drive belt
     
    Vacuum control valve set
     
    Power steering pump from mounting (Do NOT disconnect hoses)
     
    Engine wiring, and hoses, as need for access to intake manifold
     



    Fuel pressure pulsation damper
     

  4.  
  5. Disconnect the starter wire from the intake manifold stay. Remove the manifold stay.
  6.  
  7. Remove 7 bolts and 2 nuts and remove the intake manifold and delivery pipe and gasket.
  8.  

To install:

  1. Position a new gasket and the intake manifold and delivery pipe assembly into position.
  2.  
  3. Install the 7 bolts and 2 nuts; torque to 21 ft. lbs. (28 Nm).
  4.  
  5. Insert the water bypass hose between the No. 2 and No. 3 intake ports of the manifold and delivery pipe.
  6.  
  7. Install the manifold stay and torque the bolts to 30 ft. lbs. (40 Nm).
  8.  
  9. Reconnect the starter wire to the manifold stay.
  10.  
  11. Reinstall the remaining components in reverse of the removal procedure.
  12.  

3.0L (1MZ-FE) Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Coolant
     
    Throttle/accelerator cable from the throttle body
     
    Air cleaner hose at the air intake chamber and remove it
     
    All lines and hoses. Tag them for installation.
     
    Idle Speed Control (ISC) valve and the throttle body
     
    Exhaust Gas Recirculation (EGR) valve and vacuum modulator
     
    Cylinder head rear plate
     
    Intake chamber stays, any wires, then, the air intake chamber
     
    Fuel injection delivery pipe and the injectors
     
    Water outlet and the bypass outlet
     
    2 bolts and the No. 2 idler pulley bracket stay
     
    8 bolts and 4 nuts, then lift out the intake manifold
     

  4.  

To install:

  1. Thoroughly clean the intake manifold and cylinder head surfaces. Using a machinist's straight edge and a feeler gauge, check the surface of the intake manifold for warpage. If the warpage is greater than 0.0039 in. (0.10mm), replace the intake manifold.
  2.  
  3. Place new gaskets onto the intake manifold and position the intake manifold between the cylinder heads. Tighten the nuts and bolts to 13 ft. lbs. (18 Nm). Tighten the No. 2 pulley bracket bolts to 13 ft. lbs. (18 Nm).
  4.  
  5. Install or connect the following:

    Water bypass outlet and tighten the bolts to 74 inch lbs. (8.3 Nm). Tighten the water outlet to 74 inch lbs. (8 Nm).
     
    Injectors and delivery pipe
     
    Air intake chamber and tighten the 2 bolts and 2 nuts to 32 ft. lbs. (43 Nm); use an 8mm hex wrench
     
    Chamber stays and tighten the mounting bolts to 29 ft. lbs. (39 Nm)
     
    Remaining components. Tighten the emission control valve set to 73 inch lbs. (8 Nm).
     
    All hoses
     
    Accelerator cable, if equipped with automatic transaxle
     
    Coolant
     
    Negative battery cable
     

  6.  

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Coolant
     
    Throttle/accelerator cable from the throttle body
     
    Air cleaner hose at the air intake chamber and remove it
     
    All lines and hoses. Tag them for installation.
     
    Idle Speed Control (ISC) valve and the throttle body.
     
    Exhaust Gas Recirculation (EGR) valve and vacuum modulator
     
    Distributor
     
    Cylinder head rear plate
     
    Intake chamber stays, any wires, then, the air intake chamber
     
    Fuel injection delivery pipe and the injectors.
     
    Water outlet and the bypass outlet.
     
    2 bolts and the No. 2 idler pulley bracket stay.
     
    8 bolts and 4 nuts, then lift out the intake manifold.
     

  4.  

To install:

  1. Thoroughly clean the intake manifold and cylinder head surfaces. Using a machinist's straight edge and a feeler gauge, check the surface of the intake manifold for warpage. If the warpage is greater than 0.0039 in. (0.10mm), replace the intake manifold.
  2.  
  3. Place new gaskets onto the intake manifold and position the intake manifold between the cylinder heads. Tighten the nuts and bolts to 13 ft. lbs. (18 Nm). Tighten the No. 2 pulley bracket bolts to 13 ft. lbs. (18 Nm).
  4.  
  5. Install or connect the following:

    Water bypass outlet and tighten the bolts to 74 inch lbs. (8.3 Nm). Tighten the water outlet to 74 inch lbs. (8 Nm).
     
    Injectors and delivery pipe.
     
    Air intake chamber and tighten the 2 bolts and 2 nuts to 32 ft. lbs. (43 Nm); use an 8mm hex wrench.
     
    Chamber stays and tighten the mounting bolts to 29 ft. lbs. (39 Nm).
     
    Remaining components. Tighten the emission control valve set to 73 inch lbs. (8 Nm).
     
    All hoses.
     
    Accelerator cable, if equipped with automatic transaxle
     
    Coolant
     
    Negative battery cable
     

  6.  

3gr-Fse Engine


Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-3.0L (3GR-FSE) engine

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Relieve fuel system pressure.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable. Wait at least 90 seconds before performing any other work.
     
    Coolant
     
    Cool air intake duct seal
     
    Left and right engine room side covers
     
    V-bank cover
     
    No. 1 air cleaner inlet
     

  6.  
  7. Remove the air cleaner assembly with hose as follows:
    1. Disconnect the ventilation hose from the cylinder head.
    2.  
    3. Disconnect the MAF meter connector.
    4.  
    5. Disconnect the clamp from the air cleaner.
    6.  
    7. Disconnect the EVAP VSV.
    8.  
    9. Loosen the hose clamp.
    10.  
    11. Remove the 3 bolts and air cleaner case.

      No. 1 water by-pass hose
       
      No. 2 water by-pass hose
       
      Rear engine cover
       
      No. 3 water by-pass pipe
       
      No. 4 water by-pass pipe
       

    12.  

  8.  
  9. Remove intake air surge tank as follows:
    1. Remove the 2 bolts and intake manifold stay.
    2.  
    3. Remove the 4 bolts and 2 surge tank stays.
    4.  
    5. Using a 5mm hexagon socket wrench, remove the 7 bolts, 2 nuts and gasket.
    6.  

  10.  
  11. Remove the 4 bolts, 2 nuts, intake manifold and gasket.
    WARNING
    Cover the cylinder head intake port to prevent foreign matter from entering it.

  12.  

To install:

  1. Place new gaskets onto the intake manifold and position the intake manifold between the cylinder heads. Tighten the nuts and bolts to 15 ft. lbs. (21 Nm).
  2.  
  3. Install the intake air surge tank as follows:
    1. Install a new gasket to the intake air surge tank.
    2.  
    3. Install the intake air surge tank with the 2 nuts. Torque the 2 nuts to 13 ft. lbs. (18 Nm).
    4.  
    5. Using a 5mm hexagon socket wrench, install the 7 bolts. Torque the bolts to 12 ft. lbs. (16 Nm).
    6.  
    7. Install the 2 surge tank stay to the intake air surge tank. Torque the 4 bolt to 15 ft. lbs. (21 Nm).
    8.  
    9. Install the intake manifold stay with 2 bolts and torque to 7 ft. lbs. (10 Nm).
    10.  

  4.  
  5. Install or connect the following:

    No. 4 water by-pass pipe
     
    No. 3 water by-pass pipe
     
    Rear engine cover
     
    No. 2 water by-pass hose
     
    No. 1 water by-pass hose
     
    Air cleaner assembly
     
    No. 1 air cleaner inlet
     
    V-bank cover
     
    Left and right engine room side covers
     
    Cool air intake duct seal
     
    Negative battery cable
     

  6.  
  7. Refill the cooling system. Start the engine and check for leaks and proper operation.
  8.  
  9. Check the function of the throttle body unit
  10.  
  11. System initialization
  12.  

3MZ-FE Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable. Wait at least 90 seconds before performing any other work
     
    Oil pan protector
     
    Engine undercover
     
    Coolant
     
    Battery clamp cover
     
    Air cleaner inlet
     
    Lower radiator air deflector
     
    RF wheel
     
    V bank cover by removing the bolt and 2 cap nuts
     
    Air cleaner and intake air connector assembly
     
    Emission control valve
     
    Air intake surge tank
     
    Engine stabilizer control rod
     
    Fuel pipe
     
    Heater inlet water hose
     
    Battery ground cable form the engine
     
    6 fuel injector connectors
     
    Remove intake bolts following the proper sequence as shown.
     


    Click image to see an enlarged view

    Fig. Intake bolt removal sequence-3.3L (3MZ-FE) Engine

    Water outlet
     
    Radiator reserve tank pipe
     
    Upper radiator hose
     
    Engine coolant temp sensor
     
    Water outlet housing
     
    Knock sensor
     
    Gently remove the intake manifold
     

  6.  

To install:

  1. Install or connect the following:

    Two knock sensors and wiring connectors Torque to: 14 ft. lbs (20 Nm)
     

  2.  
  3. Install water outlet
    1. Install 2 new gaskets to the cylinder heads
    2.  
    3. Install water outlet with water by-pass hose
    4.  
    5. Tighten 2 bolts, 2 nuts and 2 washers to 11 ft. lbs. (15 Nm)
    6.  
    7. Connect engine temperature connector
    8.  
    9. Connect radiator reserve tank connector
    10.  
    11. Radiator hose
    12.  

  4.  
  5. Install Intake Manifold
  6.  
  7. Install or connect the following:

    9 bolts, 2 nuts and 2 washers; torque to 11 ft. lbs. (15 Nm)
     

  8.  


NOTE
Using several steps, tighten the bolts and nuts uniformly in sequence



Click image to see an enlarged view

Fig. Intake manifold tightening sequence-3.3L (3MZ-FE) Engine



Retighten 9 bolts and 2 nuts to 11 ft. lbs. (15 Nm)
 
Fuel pipe making sure the connector is seated until it clicks.
 

  1. Install or connect the following:

    Engine stabilizing control rod; torque bolt -A- to 17 ft. lbs. (23 Nm) and bolt -B- to 47 ft. lbs. (64 Nm)
     


    Click image to see an enlarged view

    Fig. Tightening procedure for Engine Stabilizing Rod -3.3L (3MZ-FE) Engine

    Intake air surge tank
     
    Emission control valve set
     
    Air Cleaner assembly
     
    Vacuum hoses
     
    Battery negative wire
     
    Front center suspension upper brace
     
    Engine coolant
     
    V-bank cover sub-assembly
     

  2.  
  3. Run engine and check for coolant and fuel leaks
  4.  
  5. System initialization
  6.  

3uz-FE Engine


Click image to see an enlarged view

Fig. Exploded view of the intake manifold mounting and related components-4.3L (3UZ-FE) Engine

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

    Negative battery cable
     
    Engine under cover
     
    Coolant
     
    V-bank cover
     
    Air cleaner assembly and connectors
     
    Throttle body assembly
     

  6.  
  7. Disconnect the fuel inlet hose (rear fuel pipe) from the fuel main tube.
  8.  
  9. Remove and disconnect the following:

    VSV connector for EVAP
     
    EVAP hose from VSV
     
    VSV from upper intake manifold
     
    4 V-bank cover brackets
     
    Engine wiring protector (LH side) from the upper intake manifold and camshaft bearing cap
     
    2 wire clamps (RH side) from the brackets on the delivery pipe
     
    Engine wire protector (rear side) from the rear water bypass joint and the RH cylinder head
     
    VSV connector for the ACIS
     
    8 injector connectors
     

  10.  
  11. Remove the 6 bolts and 4 nuts and remove the upper and lower intake manifold assembly.
  12.  
  13. If necessary, the upper intake manifold can be disassembled from the lower intake manifold by removing or disconnecting the following:

    Vacuum hose for VSV from air control valve actuator
     
    Vacuum tank hose from lower intake manifold
     
    Vacuum hose (VSV for ACIS) from clamp
     
    Wire clamp from lower intake manifold
     
    Vacuum tank and VSV assembly from ACIS
     
    Air control valve actuator
     
    15 bolts and 5 nuts to remove upper intake manifold from lower intake manifold
     

  14.  

To install:


NOTE
Always be sure to use new gaskets at each component mounting.

  1. Reassemble the upper and lower intake manifold in reverse of disassembly procedure given. Torque the upper intake manifold-to-lower manifold bolts and nuts to 13 ft. lbs. (18 Nm).
  2.  
  3. Install the vacuum tank and VSV assembly. Torque the nuts to 13 ft. lbs. (18 Nm).
  4.  
  5. Reconnect all of the wiring connectors, clamps and vacuum hoses in reverse of the removal procedure.
  6.  
  7. With new gaskets on the cylinder heads (white marks facing outward), position the upper and lower intake manifold assembly into position. Install the 6 bolts and 4 nuts and torque them to 13 ft. lbs. (18 Nm).
  8.  
  9. Reinstall and reconnect all remaining components in reverse of the removal procedure.
  10.  
  11. Refill the cooling system. Start the engine and check for leaks and proper operation.
  12.  

 
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