LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2024 >> TX 350 Base, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 74 (Engine Mechanical System (2GR-FXS) - Service Information (3 Of 3)) >> Cylinder Head >> Inspection [12/2023 - ] >> Procedure

Inspection [12/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT CYLINDER HEAD LH 
    1. Using a precision straightedge and feeler gauge, check the surfaces which contact the cylinder block sub-assembly and manifolds for warpage.
      GTY648584Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Bottom Side *b Intake Manifold Side
      *c Exhaust Manifold Side - -

      Standard Warpage

      Item Maximum Warpage Specified Condition Result
      Bottom Side 0.10 mm
      0.00394 in.      		 0.05 mm
      0.00197 in.      		 mm
      in.
      Intake Manifold Side 0.10 mm
      0.00394 in.      		 0.08 mm
      0.00315 in.      		 mm
      in.
      Exhaust Manifold Side 0.10 mm
      0.00394 in.      		 0.08 mm
      0.00315 in.      		 mm
      in.
    2. If the warpage is more than the maximum, replace the cylinder head LH.
  2. INSPECT CYLINDER HEAD LH FOR CRACKS 
    1. Using a dye penetrant, check the intake ports, exhaust ports and bottom surface of the cylinder head LH for cracks.
      GTY653442Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. If cracks are found, replace the cylinder head LH.
  3. INSPECT INTAKE VALVE 
    1. Using a micrometer, measure the diameter of the intake valve stem.
      GTY653437Courtesy 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 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.
      GTY682482Courtesy 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.
      GTY620520Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      Minimum Overall Length Specified Condition Result
      105.35 mm
      4.15 in.      		 105.85 mm
      4.17 in.      		 mm
      in.
    6. 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 exhaust valve stem.
      GTY681522Courtesy 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 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.
      GTY636597Courtesy 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.
      GTY668108Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Overall Length

      Standard Overall Length

      Minimum Overall Length Specified Condition Result
      109.90 mm
      4.33 in.      		 110.40 mm
      4.35 in.      		 mm
      in.
    6. If the overall length is less than the minimum, replace the exhaust valve.
  5. 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.
      NOTE:

      Do not rotate the intake valve while pressing it.

    • Check the valve face and intake valve seat by using the following procedure:
      GTY661778Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      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, resurface the intake valve seat.
      5. Measure the width of the contact area of the intake valve seat and valve face.

        Standard Width

        Specified Condition Result
        1.1 to 1.5 mm
        0.0433 to 0.0591 in.        		 mm
        in.

    Post-procedure1

    • None
  6. 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.
      NOTE:

      Do not rotate the exhaust valve while pressing it.

    • Check the valve face and exhaust valve seat by using the following procedure:
      GTY674960Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Width
      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
        1.1 to 1.5 mm
        0.0433 to 0.0591 in.        		 mm
        in.

    Post-procedure1

    • None
  7. INSPECT INNER COMPRESSION SPRING 
    1. Using a vernier caliper, measure the free length of the inner compression spring.
      GTY653465Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Free Length

      Minimum Free Length Specified Condition Result
      52.43 mm
      2.06 in.      		 54.53 mm
      2.15 in.      		 mm
      in.
    2. If the free length is less than the minimum, replace the inner compression spring.
    3. Using a steel square, measure the deviation of the inner compression spring.
      GTY678461Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Deviation
      *b 40 mm (1.57 in.)

      Maximum Deviation (Reference)

      Specified Condition Result
      1.4 mm
      0.0551 in.      		 mm
      in.
    4. If the deviation is more than the maximum, replace the inner compression spring.
  8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE 
    1. Using a caliper gauge, measure the inside diameter of the valve guide bush.
      GTY681528Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Valve Guide Bush Inside Diameter

      Specified Condition Result
      5.510 to 5.530 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 0.12 mm
      0.00472 in.      		 0.025 to 0.060 mm
      0.000984 to 0.00236 in.      		 mm
      in.
      Exhaust Side 0.12 mm
      0.00472 in.      		 0.030 to 0.065 mm
      0.00118 to 0.00256 in.      		 mm
      in.
    3. If the oil clearance is more than the maximum, replace the valve and valve guide bush.
scientia non olet · About LEMON Manuals