CYLINDER HEAD INSPECTION

CAUTION / NOTICE / HINT

Tech Tips

When viewed from the rear of the engine assembly, Bank 1 is on the left side and Bank 2 is on the right side.

PROCEDURE


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. Using a precision straightedge and feeler gauge, measure the warpage of the surfaces where the cylinder head contacts the cylinder block and manifold.

      A000X5CE02
      *1 Intake Side:
      *2 Exhaust Side:
      *3 Cylinder Head Lower Side:
      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. A000URQ

      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. A000YTW

      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.)

      If the diameter is not as specified, replace the valve and guide bush.

    2. A000X62E01
      *1 Margin Thickness

      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. A00103NE01
      *1 Overall Length

      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. A000XA1

      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.)

      If the diameter is not as specified, replace the valve and guide bush.

    2. A000UB0E01
      *1 Margin Thickness

      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. A000UDSE01
      *1 Overall Length

      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. A000W43E01
      *1 Width

      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 contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 to 1.5 mm (0.0433 to 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.

  5. INSPECT EXHAUST VALVE SEAT


    1. A000VB7E01
      *1 Width

      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 contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 to 1.5 mm (0.0433 to 0.0591 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.

  6. INSPECT INNER COMPRESSION SPRING


    1. A000X49

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

      Standard free length
      49.38 to 53.38 mm (1.94 to 2.10 in.)

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

    2. A000ZM2E23
      *1 Deviation
      *2 40 mm (1.57 in.)

      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 spring.

  7. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A000Y63

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

  8. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Inspect the bank 1 camshafts.


      1. Install the bank 1 camshafts.

      2. A000YU9

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

        Standard thrust clearance
        0.08 to 0.140 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 thrust surface is damaged, replace the camshaft.

    2. Inspect the bank 2 camshafts.


      1. Install the bank 2 camshafts.

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

        Standard thrust clearance
        0.08 to 0.140 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 thrust surface is damaged, replace the camshaft.