CYLINDER HEAD INSPECTION

PROCEDURE


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. Using a precision straightedge and feeler gauge, measure the warpage of the surfaces which contact the cylinder block sub-assembly and manifolds.

      A0028EBC03
      *A Bottom Side *B Intake Manifold Side
      *C Exhaust Manifold Side - -
      Standard Warpage
      Item Specified Condition
      Bottom Side 0.05 mm (0.00197 in.)
      Intake Manifold Side 0.08 mm (0.00315 in.)
      Exhaust Manifold Side 0.08 mm (0.00315 in.)
      Maximum Warpage
      Item Specified Condition
      Bottom Side 0.10 mm (0.00394 in.)
      Intake Manifold Side 0.10 mm (0.00394 in.)
      Exhaust Manifold 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. A0029F4

      Using a dye penetrant, check the intake ports, exhaust ports and bottom surface of the cylinder head sub-assembly for cracks.

      If cracks are found, replace the cylinder head sub-assembly.

  3. INSPECT INTAKE VALVE


    1. A002AJW

      Using a micrometer, measure the diameter of the valve stem.

      Standard Valve Stem Diameter
      5.470 to 5.485 mm (0.2154 to 0.2159 in.)

      If the diameter is not as specified, check the oil clearance.

    2. A002803C12
      *a Margin Thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard Margin Thickness
      1.0 mm (0.0394 in.)
      Minimum Margin Thickness
      0.5 mm (0.0197 in.)

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

    3. A0029EPC25
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard Overall Length
      105.85 mm (4.1673 in.)
      Minimum Overall Length
      105.35 mm (4.1476 in.)

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

  4. INSPECT EXHAUST VALVE


    1. A0027C5

      Using a micrometer, measure the diameter of the valve stem.

      Standard Valve Stem Diameter
      5.465 to 5.480 mm (0.2152 to 0.2157 in.)

      If the diameter is not as specified, check the oil clearance.

    2. A002CNRC28
      *a Margin Thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard Margin Thickness
      1.0 mm (0.0394 in.)
      Minimum Margin Thickness
      0.5 mm (0.0197 in.)

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

    3. A002ASLC20
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard Overall Length
      110.40 mm (4.3464 in.)
      Minimum Overall Length
      109.90 mm (4.3268 in.)

      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.

    3. A002881C01
      *a Width

      Check the valve face and intake valve seat by using the following procedure:


      1. If Prussian blue appears around the entire valve face, the valve face is concentric. If not, replace the intake valve.

      2. If Prussian blue appears around the entire intake valve seat, the intake valve seat and valve face are concentric. If not, resurface the intake valve seat.

      3. Check that the intake valve seat contacts the middle of the valve face with the width between 1.1 and 1.5 mm (0.0433 and 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.

    3. A002881C01
      *a Width

      Check the valve face and exhaust valve seat by using the following procedure:


      1. If Prussian blue appears around the entire valve face, the valve face is concentric. If not, replace the exhaust valve.

      2. If Prussian blue appears around the entire exhaust valve seat, the exhaust valve seat and valve face are concentric. If not, resurface the exhaust valve seat.

      3. Check that the exhaust valve seat contacts the middle of the valve face with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).

  7. INSPECT INNER COMPRESSION SPRING


    1. A002B40

      Using a vernier caliper, measure the free length of the inner compression spring.

      Standard Free Length
      50.55 mm (1.9902 in.)

      If the free length is not as specified, replace the inner compression spring.

    2. A002A7OC07
      *a Deviation

      Using a steel square, measure the deviation of the inner compression spring.

      Maximum Deviation
      1.75 mm (0.0689 in.)
      Maximum Angle (reference)
      2°

      If the deviation is more than the maximum, replace the inner compression spring.

  8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A0029E9

      Using a caliper gauge, measure the inside diameter of the valve guide bush.

      Standard Valve Guide Bush Inside Diameter
      5.510 to 5.530 mm (0.2169 to 0.2177 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.)

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