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Inspection [12/2021 - ]: Procedure

  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY 
    1. Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head sub-assembly contacts the cylinder block sub-assembly and manifolds.
      GTY965621Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Cylinder Head Sub-assembly Lower Side *b Intake Manifold Side
      *c Turbocharger Sub-assembly Side - -
      MAXIMUM WARPAGE

      Item Specified Condition
      Cylinder Head Sub-assembly Lower Side 0.05 mm (0.00197 in.)
      Intake Manifold Side 0.10 mm (0.00394 in.)
      Turbocharger Sub-assembly Side 0.10 mm (0.00394 in.)

      If the warpage is more than the maximum, replace the cylinder head sub-assembly.

  2. INSPECT CYLINDER HEAD FOR CRACKS 
    1. Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.

      HINT: 

      If cracked, replace the cylinder head sub-assembly.

      GTY964988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT INTAKE VALVE 
    1. Using a micrometer, measure the diameter of the valve stem.
      GTY783111Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      5.470 to 5.485 mm (0.215 to 0.216 in.)

      HINT: 

      If the valve stem diameter is not as specified, check the intake valve guide bush oil clearance.

    2. Using a vernier caliper, measure the valve head margin thickness.
      GTY801121Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Margin Thickness

      Standard Margin Thickness

      1.0 mm (0.0394 in.)

      Minimum Margin Thickness

      0.5 mm (0.0197 in.)

      HINT: 

      If the margin thickness is less than the minimum, replace the intake valve.

    3. Using a vernier caliper, measure the overall length of the intake valve.
      GTY834424Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      104.45 mm (4.11 in.)

      Minimum Overall Length

      103.95 mm (4.09 in.)

      HINT: 

      If the overall length is less than the minimum, replace the intake valve.

  4. INSPECT EXHAUST VALVE 
    1. Using a micrometer, measure the diameter of the valve stem.
      GTY783107Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      5.465 to 5.480 mm (0.215 to 0.216 in.)

      HINT: 

      If the valve stem diameter is not as specified, check the exhaust valve guide bush oil clearance.

    2. Using a vernier caliper, measure the valve head margin thickness.
      GTY827146Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Margin Thickness

      Standard Margin Thickness

      1.0 mm (0.0394 in.)

      Minimum Margin Thickness

      0.5 mm (0.0197 in.)

      HINT: 

      If the margin thickness is less than the minimum, replace the exhaust valve.

    3. Using a vernier caliper, measure the overall length of the exhaust valve.
      GTY780640Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      108.7 mm (4.28 in.)

      Minimum Overall Length

      108.2 mm (4.26 in.)

      HINT: 

      If the overall length is less than the minimum, replace the exhaust valve.

  5. INSPECT INTAKE VALVE SEAT 
    1. Apply a light coat of Prussian blue to the valve face.
    2. Lightly press the valve face against the intake valve seat.
      NOTE:

      Do not rotate the intake valve while pressing it.

    3. Check the valve face and intake valve seat by using the following procedure:
      GTY784778Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      1. If Prussian blue appears 360° around the entire intake valve face, the valve face is concentric.

        HINT: 

        If the valve face is not concentric, replace the intake valve.

      2. If Prussian blue appears 360° around the entire intake valve seat, the intake valve seat and valve face are concentric.

        HINT: 

        If the valve face is not concentric, resurface the intake valve seat.

      3. Measure the width of the contact area of the intake valve seat and valve face.

        Standard Width

        1.1 to 1.5 mm (0.0433 to 0.0591 in.)

  6. INSPECT EXHAUST VALVE SEAT 
    1. Apply a light coat of Prussian blue to the valve face.
    2. Lightly press the valve face against the exhaust valve seat.
      NOTE:

      Do not rotate the exhaust valve while pressing it.

    3. Check the valve face and exhaust valve seat by using the following procedure:
      GTY810904Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      1. If Prussian blue appears 360° around the entire exhaust valve face, the valve face is concentric.

        HINT: 

        If the valve face is not concentric, replace the exhaust valve.

      2. If Prussian blue appears 360° around the entire exhaust valve seat, the exhaust valve seat and valve face are concentric.

        HINT: 

        If the valve face is not concentric, resurface the exhaust valve seat.

      3. Measure the width of the contact area of the exhaust valve seat and valve face.

        Standard Width

        1.3 to 1.7 mm (0.0512 to 0.0669 in.)

  7. INSPECT CYLINDER HEAD INTAKE VALVE COMPRESSION SPRING 
    1. Using a vernier caliper, measure the free length of the cylinder head intake compression spring.
      GTY828900Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      53.24 mm (2.10 in.)

      NOTE:

      Compression springs come in 2 different lengths. Make sure all compression springs are the same length when replacing them.

    2. Using a steel square, measure the deviation of the cylinder head intake compression spring.
      GTY817258Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 40 mm (1.57 in.)

      Maximum Deviation (Reference)

      1.0 mm (0.0394 in.)

      HINT: 

      If the deviation is more than the maximum, replace the cylinder head intake compression spring.

  8. INSPECT CYLINDER HEAD EXHAUST VALVE COMPRESSION SPRING 
    1. Using a vernier caliper, measure the free length of the cylinder head exhaust compression spring.
      GTY828900Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      57.78 mm (2.27 in.)

      NOTE:

      Compression springs come in 2 different lengths. Make sure all compression springs are the same length when replacing them.

    2. Using a steel square, measure the deviation of the cylinder head exhaust compression spring.
      GTY817258Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 40 mm (1.57 in.)

      Maximum Deviation (Reference)

      1.0 mm (0.0394 in.)

      HINT: 

      If the deviation is more than the maximum, replace the cylinder head exhaust compression spring.

  9. INSPECT VALVE GUIDE BUSH OIL CLEARANCE 
    1. Using a caliper gauge, measure the inside diameter of the valve guide bush.
      GTY782556Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Guide Bush Inside Diameter

      5.510 to 5.530 mm (0.217 to 0.218 in.)

    2. Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

      Standard Oil Clearance

      Item Specified Condition
      Intake 0.025 to 0.060 mm (0.000984 to 0.00236 in.)
      Exhaust 0.030 to 0.065 mm (0.00118 to 0.00256 in.)

      Maximum Oil Clearance

      Item Specified Condition
      Intake 0.08 mm (0.00315 in.)
      Exhaust 0.10 mm (0.00394 in.)

      HINT: 

      If the oil clearance is more than the maximum, replace the valve and valve guide bush.

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