CYLINDER HEAD INSPECTION

PROCEDURE

  1. INSPECT CYLINDER HEAD FOR FLATNESS

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

      A389949E01

      Maximum Warpage

      Item

      Specified Condition

      Cylinder block side

      0.05 mm (0.00197 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.

  2. INSPECT CYLINDER HEAD FOR CRACKS

    1. A150952

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

      If cracked, replace the cylinder head.

  3. INSPECT VALVE SEATS

    1. A146287E01

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

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

      Tip:

      Do not rotate the valve while pressing the valve.

    3. Check the valve face and valve seat.

      1. Intake Side:

        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 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

        If not, correct the valve seat.

      2. Exhaust Side:

        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 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

        If not, correct the valve seat.

      3. 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.

  4. INSPECT CAMSHAFT THRUST CLEARANCE

    1. Install the camshaft housing assembly (Click here).

      Tip:

      Do not use seal packing when installing the camshaft housing, as the installation is temporary.

    2. A205904

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

      Standard thrust clearance

      0.06 to 0.155 mm (0.00236 to 0.00610 in.)

      Maximum thrust clearance

      0.17 mm (0.00669 in.)

      If the thrust clearance is more than the maximum, replace the camshaft housing sub-assembly.

  5. INSPECT COMPRESSION SPRING

    1. A333833

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

      Standard free length

      51.9 mm (2.04 in.)

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

    2. A319225E13

      Using a steel square, measure the deviation of the compression spring at position shown in the illustration.

      Maximum deviation

      1.3 mm (0.0512 in.)

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

  6. INSPECT INTAKE VALVE

    1. A121380E01

      Using a vernier caliper, measure the overall length of the valve.

      Standard overall length

      109.34 mm (4.30 in.)

      Minimum overall length

      108.84 mm (4.29 in.)

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

    2. A121378

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

      Valve stem diameter

      5.470 to 5.485 mm (0.215 to 0.216 in.)

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

    3. A389950E01

      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 valve.

  7. INSPECT EXHAUST VALVE

    1. A121383E01

      Using a vernier caliper, measure the overall length of the valve.

      Standard overall length

      108.25 mm (4.26 in.)

      Minimum overall length

      107.75 mm (4.24 in.)

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

    2. A121381

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

      Valve stem diameter

      5.465 to 5.480 mm (0.215 to 0.216 in.)

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

    3. A121382E01

      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 valve.

  8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE

    1. A150966

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

      Standard bush inside diameter

      5.510 to 5.530 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

      0.080 mm (0.00315 in.)

      Exhaust

      0.085 mm (0.00335 in.)

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