CYLINDER HEAD INSPECTION


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. A0160FDE01

      Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces of the cylinder block and manifold.

      Standard Warpage
      Item Specified Condition
      Cylinder head lower side 0.05 mm (0.00197 in.)
      Intake side 0.08 mm (0.00315 in.)
      Exhaust side 0.05 mm (0.00197 in.)
      Maximum warpage
      0.10 mm (0.00394 in.)

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

    2. A0162NB

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

      If cracked, replace the cylinder head.

  2. INSPECT INTAKE VALVE


    1. A015Z5M

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

      Standard valve stem diameter
      5.470 to 5.485 mm (0.215 to 0.216 in.)
    2. A0160Z0E01

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

      Standard margin thickness
      1.25 mm (0.0492 in.)
      Minimum margin thickness
      0.50 mm (0.0197 in.)

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

    3. A0161EZE01

      Using a vernier caliper, measure the valve's overall length.

      Standard overall length
      105.85 mm (4.17 in.)
      Minimum overall length
      105.35 mm (4.15 in.)

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

  3. INSPECT EXHAUST VALVE


    1. A0160LN

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

      Standard valve stem diameter
      5.465 to 5.480 mm (0.215 to 0.216 in.)
    2. A0161VHE01

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

      Standard margin thickness
      1.4 mm (0.0551 in.)
      Minimum margin thickness
      0.50 mm (0.0197 in.)

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

    3. A016272E01

      Using a vernier caliper, measure the valve's overall length.

      Standard overall length
      110.40 mm (4.35 in.)
      Minimum overall length
      109.90 mm (4.33 in.)

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

  4. INSPECT INTAKE VALVE SEAT


    1. A01631PE01

      Apply a light coat of Prussian blue to the valve face.

    2. Lightly press the valve face against the valve seat.

      Tech Tips

      Do not rotate the valve while pressing the valve.

    3. Check the valve face and valve seat.


      1. Check that the 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.).

        If not, correct the valve seat.

      2. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.

        If not, correct the valve seat Click here.

  5. INSPECT EXHAUST VALVE SEAT


    1. A0160T7E01

      Apply a light coat of Prussian blue to the valve face.

    2. Lightly press the valve face against the valve seat.

    3. Check the valve face and valve seat.


      1. Check that the valve seat contacts the middle of the valve face with the width between 1.3 and 1.7 mm (0.0512 and 0.0669 in.).

        If not, correct the valve seat.

      2. Check that the contact surface of the valve seat and valve face are even around the entire valve seat.

        If not, correct the valve seat Click here.

  6. INSPECT INNER COMPRESSION SPRING


    1. A015YQO

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

      Standard Free Length
      Item Standard Condition
      Intake side 47.86 mm (1.88 in.)
      Exhaust side 47.24 mm (1.86 in.)

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

    2. A0160APE02

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

      Maximum deviation
      1.0 mm (0.0394 in.)
      Maximum angle (reference)
      2°

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

  7. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A015Z0W

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

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

  8. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Inspect the bank 1 camshafts.


      1. Install the bank 1 camshafts.

      2. A0162F4

        Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

        Standard thrust clearance
        0.08 to 0.14 mm (0.00315 to 0.00551 in.)
        Maximum thrust clearance
        0.15 mm (0.00591 in.)

        If the thrust clearance is greater than the maximum, replace the cylinder head. If the camshaft thrust surface is damaged, replace the camshaft.

    2. Inspect the bank 2 camshafts.


      1. Install the bank 2 camshafts.

      2. A01600T

        Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

        Standard thrust clearance
        0.08 to 0.14 mm (0.00315 to 0.00551 in.)
        Maximum thrust clearance
        0.15 mm (0.00591 in.)

        If the thrust clearance is greater than the maximum, replace the cylinder head. If the camshaft thrust surface is damaged, replace the camshaft.