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Inspection [11/2021 - ]: Procedure

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  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, intake manifold and turbocharger sub-assembly.
      GTY1077241Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Bottom Side *b Intake Manifold Side
      *c Turbocharger Sub-assembly Side - -

      Maximum Warpage

      Item Specified Condition
      Bottom 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.)
    2. If the warpage is more than the maximum, replace the cylinder head sub-assembly.
    3. Using a dye penetrant, check the intake ports, exhaust ports and cylinder head sub-assembly surface for cracks.
      GTY1076825Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. If cracks are found, replace the cylinder head sub-assembly.
  2. INSPECT INTAKE VALVE COMPRESSION SPRING 
    1. Using a vernier caliper, measure the free length of the intake valve compression spring.
      GTY1076814Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      58.84 mm (2.32 in.)

    2. If the free length is not as specified, replace the intake valve compression spring.
    3. Using a steel square, measure the deviation of the intake valve compression spring.
      GTY1076223Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 43.74 mm (1.72 in.)

      Maximum Deviation (Reference)

      1.0 mm (0.0394 in.)

    4. If the deviation is more than the maximum, replace the intake valve compression spring.
  3. INSPECT EXHAUST VALVE COMPRESSION SPRING 
    1. Using a vernier caliper, measure the free length of the exhaust valve compression spring.

      Standard Free Length

      57.86 mm (2.28 in.)

      GTY1076813Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. If the free length is not as specified, replace the exhaust valve compression spring.
    3. Using a steel square, measure the deviation of the exhaust valve compression spring.

      Maximum Deviation (Reference)

      0.1 mm (0.00394 in.)

      GTY1076430Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 42.07 mm (1.66 in.)
    4. If the deviation is more than the maximum, replace the exhaust valve compression spring.
  4. INSPECT INTAKE VALVE 
    1. Using a micrometer, measure the diameter of the intake valve stem.
      GTY1077512Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      5.470 to 5.485 mm (0.215 to 0.216 in.)

    2. If the intake valve stem diameter is not as specified, check the intake valve guide bush oil clearance.
    3. Using a vernier caliper, measure the intake valve head margin thickness.
      GTY1077013Courtesy 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.)

    4. If the margin thickness is less than the minimum, replace the intake valve.
    5. Using a vernier caliper, measure the overall length of the intake valve.
      GTY1077149Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      110.35 mm (4.34 in.)

      Minimum Overall Length

      109.85 mm (4.32 in.)

    6. If the overall length is less than the minimum, replace the intake valve.
  5. INSPECT EXHAUST VALVE 
    1. Using a micrometer, measure the diameter of the exhaust valve stem.
      GTY1076787Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      5.465 to 5.480 mm (0.215 to 0.216 in.)

    2. If the exhaust valve stem diameter is not as specified, check the exhaust valve guide bush oil clearance.
    3. Using a vernier caliper, measure the exhaust valve head margin thickness.
      GTY1077354Courtesy 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.)

    4. If the margin thickness is less than the minimum, replace the exhaust valve.
    5. Using a vernier caliper, measure the overall length of the exhaust valve.
      GTY1076768Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      109.0 mm (4.29 in.)

      Minimum Overall Length

      108.5 mm (4.27 in.)

    6. If the overall length is less than the minimum, replace the exhaust valve.
  6. INSPECT VALVE GUIDE BUSH OIL CLEARANCE 
    1. Using a caliper gauge, measure the inside diameter of the valve guide bush.
      GTY1076783Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Guide Bush Inside Diameter

      5.51 to 5.53 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 Side 0.025 to 0.060 mm (0.000984 to 0.00236 in.)
      Exhaust Side 0.030 to 0.065 mm (0.00118 to 0.00256 in.)

      Maximum Oil Clearance

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

      HINT: 

      Oil clearance = Valve guide bush inside diameter - Valve stem diameter

    3. If the oil clearance is more than the maximum, replace the valve and valve guide bush.
  7. 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.
      GTY1076308Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      NOTE:

      Do not rotate the valve while pressing it.

    3. Check the valve face and intake valve seat by using the following procedure:
      1. If Prussian blue appears 360° around the entire intake valve face, the valve face is concentric.
      2. If the valve face is not concentric, replace the intake valve.
      3. If Prussian blue appears 360° around the entire intake valve seat, the intake valve seat and valve face are concentric.
      4. If the valve face is not concentric, replace the cylinder head sub-assembly.
      5. 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.)

  8. 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.
      GTY1076939Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      NOTE:

      Do not rotate the valve while pressing it.

    3. Check the valve face and exhaust valve seat by using the following procedure:
      1. If Prussian blue appears 360° around the entire exhaust valve face, the valve face is concentric.
      2. If the valve face is not concentric, replace the exhaust valve.
      3. If Prussian blue appears 360° around the entire exhaust valve seat, the exhaust valve seat and valve face are concentric.
      4. If the valve face is not concentric, resurface the exhaust valve seat.
      5. Measure the width of the contact area of the exhaust valve seat and valve face.

        Standard Width

        1.2 to 1.6 mm (0.0472 to 0.0630 in.)

  9. INSPECT CAMSHAFT THRUST CLEARANCE 
    1. Clean the No. 1 camshaft bearing cap, No. 2 camshaft bearing cap, No. 3 camshaft bearing caps, No. 4 camshaft bearing cap, No. 5 camshaft bearing cap, camshaft housing sub-assembly and camshaft journals.
    2. Place the intake camshaft sub-assembly and exhaust camshaft sub-assembly on the camshaft housing sub-assembly on the cylinder head sub-assembly.
    3. Install the camshaft bearing caps.

      See step  22

    4. Install the camshaft housing sub-assembly.

      See step  23

    5. Using a dial indicator, measure the thrust clearance while moving the intake camshaft sub-assembly and exhaust camshaft sub-assembly back and forth.
      GTY1076774Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Thrust Clearance

      Item Specified Condition
      Intake Camshaft Sub-assembly 0.04 to 0.17 mm (0.00157 to 0.00669 in.)
      Exhaust Camshaft Sub-assembly 0.04 to 0.17 mm (0.00157 to 0.00669 in.)

      Maximum Thrust Clearance

      Item Specified Condition
      Intake Camshaft Sub-assembly 0.2 mm (0.00787 in.)
      Exhaust Camshaft Sub-assembly 0.2 mm (0.00787 in.)
    6. If the thrust clearance is more than the maximum, replace the camshaft housing sub-assembly. If the thrust surface is damaged, replace the intake camshaft sub-assembly or exhaust camshaft sub-assembly.
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