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Inspection [12/2022 - 03/2023]: 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, intake manifold and exhaust manifold.
      GTY1273656Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Bottom Side *b Intake Manifold Side
      *c Exhaust Manifold Side - -

      Maximum Warpage

      Item Specified Condition Result
      Bottom side 0.05 mm
      0.00197 in.      		 mm
      in.
      Intake manifold side 0.10 mm
      0.00394 in.      		 mm
      in.
      Exhaust manifold side 0.10 mm
      0.00394 in.      		 mm
      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.
      GTY756887Courtesy 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.
      GTY756890Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      Specified Condition Result
      58.81 mm
      2.32 in.      		 mm
      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.
      GTY757686Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 37 mm (1.46 in.)

      Maximum Deviation (Reference)

      Specified Condition Result
      1.0 mm
      0.0394 in.      		 mm
      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.
      GTY756890Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      Specified Condition Result
      58.81 mm
      2.32 in.      		 mm
      in.
    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.
      GTY757686Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 37 mm (1.46 in.)

      Maximum Deviation (Reference)

      Specified Condition Result
      1.0 mm
      0.0394 in.      		 mm
      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.
      GTY756892Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      Specified Condition Result
      5.470 to 5.485 mm
      0.215 to 0.216 in.      		 mm
      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.
      GTY761889Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Margin Thickness

      Standard Margin Thickness

      Minimum Margin Thickness Specified Condition Result
      0.5 mm
      0.0197 in.      		 1.0 mm
      0.0394 in.      		 mm
      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.
      GTY767342Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      Minimum Overall Length Specified Condition Result
      101.95 mm
      4.01 in.      		 102.45 mm
      4.03 in.      		 mm
      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.
      GTY948113Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Stem Diameter

      Specified Condition Result
      5.465 to 5.480 mm
      0.215 to 0.216 in.      		 mm
      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.
      GTY743223Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Margin Thickness

      Standard Margin Thickness

      Minimum Margin Thickness Specified Condition Result
      0.5 mm
      0.0197 in.      		 1.0 mm
      0.0394 in.      		 mm
      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.
      GTY768815Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      Minimum Overall Length Specified Condition Result
      105.9 mm
      4.17 in.      		 106.4 mm
      4.19 in.      		 mm
      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.
      GTY838215Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Guide Bush Inside Diameter

      Specified Condition Result
      5.51 to 5.53 mm
      0.217 to 0.218 in.      		 mm
      in.
    2. Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

      Standard Oil Clearance

      Item Maximum Oil Clearance Specified Condition Result
      Intake Side 0.080 mm
      0.00315 in.      		 0.025 to 0.060 mm
      0.000984 to 0.00236 in.      		 mm
      in.
      Exhaust Side 0.10 mm
      0.00394 in.      		 0.030 to 0.065 mm
      0.00118 to 0.00256 in.      		 mm
      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 

    Pre-procedure1

    • Apply a light coat of Prussian blue to the valve face.
    • Lightly press the valve face against the intake valve seat.
      GTY784780Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      NOTE:

      Do not rotate the valve while pressing it.

    • 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

        Specified Condition Result
        1.0 to 1.4 mm
        0.0394 to 0.0551 in.        		 mm
        in.

    Post-procedure1

    • None
  8. INSPECT EXHAUST VALVE SEAT 

    Pre-procedure1

    • Apply a light coat of Prussian blue to the valve face.
    • Lightly press the valve face against the exhaust valve seat.
      GTY778981Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      NOTE:

      Do not rotate the valve while pressing it.

    • 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

        Specified Condition Result
        1.2 to 1.6 mm
        0.0472 to 0.0630 in.        		 mm
        in.

    Post-procedure1

    • None
  9. INSPECT CAMSHAFT THRUST CLEARANCE 

    Pre-procedure1

    • Clean the No. 1 camshaft bearing cap, No. 2 camshaft bearing cap, 2 No. 3 camshaft bearing caps, No. 4 camshaft bearing cap, camshaft housing sub-assembly and camshaft journals.
    • Place the intake camshaft sub-assembly and exhaust camshaft sub-assembly on the camshaft housing sub-assembly on the cylinder head sub-assembly.
    • Install the camshaft bearing caps.

      HINT: 

      Refer to PROCEDURE - Step 24

    • Install the camshaft housing sub-assembly.

      HINT: 

      Refer to PROCEDURE - Step 25

    • Using a dial indicator, measure the thrust clearance while moving the intake camshaft sub-assembly and exhaust camshaft sub-assembly back and forth.
      GTY824967Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Thrust Clearance

      Item Maximum Thrust Clearance Specified Condition Result
      Intake camshaft sub-assembly 0.22 mm
      0.00866 in.      		 0.04 to 0.17 mm
      0.00157 to 0.00669 in.      		 mm
      in.
      Exhaust camshaft sub-assembly 0.22 mm
      0.00866 in.      		 0.04 to 0.17 mm
      0.00157 to 0.00669 in.      		 mm
      in.
    • 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.

    Post-procedure1

    • None
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