2008 Lexus GX 470FACTORY OEM SERVICE PROCEDURE

Knock Sensor, Intake Manifold: Removal

  1. DISCHARGE FUEL SYSTEM PRESSURE  (See REMOVAL )
  2. DRAIN ENGINE COOLANT  (See REPLACEMENT )
  3. REMOVE V-BANK COVER SUB-ASSEMBLY  (See REMOVAL )
  4. REMOVE AIR CLEANER HOSE ASSEMBLY 
    1. Disconnect the vacuum hoses (for the power steering idle-up and fuel pressure regulator) and ventilation hose.
    2. Remove the air cleaner hose assembly.
  5. DISCONNECT FUEL HOSE  (See REMOVAL )
  6. DISCONNECT FUEL HOSE NO.2  (See REMOVAL )
  7. DISCONNECT CONNECTORS FROM INTAKE MANIFOLD 
    1. Disconnect the throttle control connector.
    2. Disconnect the purge VSV connector.
    3. Disconnect the 8 injector connectors.
    4. Disconnect the ECT sensor connector.
    5. Disconnect the 2 VSV connectors for the air injection system.
    6. Disconnect the 8 ignition coil connectors.
    7. Disconnect the 2 air fuel ratio sensor connectors.
  8. DISCONNECT HOSES FROM INTAKE MANIFOLD 
    1. Disconnect the vacuum hose [A] from the fuel pressure regulator.
    2. Disconnect the PCV hoses [B] from the PCV valve on the LH cylinder head.
    3. Disconnect the EVAP hose (from the charcoal canister) [C] from the VSV for the EVAP.
    4. Disconnect the 2 vacuum hoses [D] from the VSV for the air injection system.
      Fig 1: Identifying Vacuum Hose, PCV Hoses , EVAP Hose And Vacuum Hoses
      G04968231Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. REMOVE INTAKE MANIFOLD 
    1. Disconnect the 2 water by-pass hoses from the throttle body.
      Fig 2: Locating Water By-Pass Hoses
      G04968232Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the 2 wire clamps from the wire clamp bracket on the RH delivery pipe.
      Fig 3: Locating Wire Clamps
      G04968233Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Remove the bolt and nut holding the engine wire protector from the intake manifold and cylinder head.
    4. Remove the 2 bolts and ground cables from the RH and LH cylinder heads.
    5. Remove the bolt and V-bank cover bracket from the intake manifold.
      Fig 4: Locating Cylinder Heads Bolts
      G04968234Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Disconnect the engine wire from the engine hanger and wire bracket.
      Fig 5: Locating Engine Wire On Engine Hanger And Wire Bracket
      G04968235Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Remove the bolt and wire bracket from the intake manifold.
    8. Remove the 6 bolts, 4 nuts, intake manifold assembly and 2 gaskets.
  10. REMOVE AIR PUMP ASSEMBLY WITH BRACKET  (See REMOVAL )
    Fig 6: Locating Intake Manifold Assembly Bolts And Nuts
    G04968236Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  11. REMOVE KNOCK SENSOR 
    1. Disconnect the 2 knock sensor connectors.
    2. Remove the 2 nuts and 2 knock sensors.
      Fig 7: Removing Knock Sensors Nuts
      G04968237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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