CYLINDER HEAD INSPECTION


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. A017F29E01

      Using a precision straight edge and feeler gauge, measure the warpage of the contact surface of the cylinder block sub-assembly and manifolds.

      Standard warpage
      Item Warpage
      Cylinder head lower 0.05 mm (0.0020 in.)
      Intake 0.08 mm (0.0031 in.)
      Exhaust 0.08 mm (0.0031 in.)
      Maximum warpage
      Item Warpage
      Cylinder head lower 0.10 mm (0.0039 in.)
      Intake 0.10 mm (0.0039 in.)
      Exhaust 0.10 mm (0.0039 in.)

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

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. A017E29

      Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.

      If cracked, replace the cylinder head sub-assembly.

  3. INSPECT INTAKE VALVE


    1. A017BZ7

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

      Valve stem diameter
      5.470 to 5.485 mm (0.2154 to 0.2159 in.)

      If the valve stem is not as specified, check the oil clearance.

    2. A017F2IE01

      Using vernier calipers, measure the valve head margin thickness.

      Standard margin thickness
      1.0 mm (0.039 in.)
      Minimum margin thickness
      0.5 mm (0.0197 in.)

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

    3. A017DS5E01

      Using vernier calipers, measure the valve's 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. A017CA2

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

      Valve stem diameter
      5.465 to 5.480 mm (0.2151 to 0.2157 in.)

      If the valve stem is not as specified, check the oil clearance.

    2. A017DYDE01

      Using vernier calipers, measure the valve head margin thickness.

      Standard margin thickness
      1.0 mm (0.039 in.)
      Minimum margin thickness
      0.5 mm (0.0197 in.)

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

    3. A017BRBE01

      Using vernier calipers, measure the valve's 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 valve seat.

    3. A017G9YE01

      Check the valve face and valve spring 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 valve.

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

      3. Check that the valve spring seat contacts in the middle of the valve face with the width between 1.1 and 1.5 mm (0.043 and 0.059 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 valve spring seat.

    3. A017G9YE01

      Check the valve face and valve spring 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 valve.

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

      3. Check that the valve spring seat contacts in the middle of the valve face with the width between 1.1 and 1.5 mm (0.043 and 0.059 in.).

  7. INSPECT INNER COMPRESSION SPRING


    1. A017FYX

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

      Free length
      45.46 mm (1.7898 in.)

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

    2. A017DF2E01

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

      Maximum deviation
      1.0 mm (0.039 in.)
      Maximum angle (reference)
      2°

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

  8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A017BBK

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

      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 clearance
      Item Clearance
      Intake 0.025 to 0.060 mm (0.0010 to 0.0024 in.)
      Exhaust 0.030 to 0.065 mm (0.0012 to 0.0026 in.)
      Maximum oil clearance
      Item Clearance
      Intake 0.08 mm (0.0032 in.)
      Exhaust 0.10 mm (0.0039 in.)

      For intake side:

      If the clearance is greater than the maximum, replace the intake valve and intake valve guide bush.

      For exhaust side:

      If the clearance is greater than the maximum, replace the exhaust valve and exhaust valve guide bush.