CYLINDER HEAD INSPECTION

PROCEDURE


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head sub-assembly contacts the cylinder block sub-assembly, intake manifold and exhaust manifold converter sub-assembly (TWC: Front Catalyst).

      A01W4V0E01
      Text in Illustration
      *a Cylinder Block Sub-assembly Side *b Intake Manifold Side
      *c Exhaust Manifold Converter Sub-assembly (TWC: Front Catalyst) Side - -
      Maximum Warpage
      Item Specified Condition
      Cylinder block sub-assembly side 0.05 mm (0.00197 in.)
      Intake manifold side 0.10 mm (0.00394 in.)
      Exhaust manifold converter sub-assembly (TWC: Front Catalyst) side 0.10 mm (0.00394 in.)

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

    2. A01W45K

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

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

  2. INSPECT COMPRESSION SPRING


    1. A01W3RF

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

      Standard Free Length
      50.78 mm (2.00 in.)

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

    2. A01W0ITE02
      Text in Illustration
      *a Deviation
      *b 36.7 mm (1.44 in.)

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

      Maximum Deviation
      1.28 mm (0.0504 in.)
      Maximum Angle
      2°

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

  3. INSPECT INTAKE VALVE


    1. A01W0CP

      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 valve stem diameter is not as specified, check the intake valve guide bush oil clearance.

    2. A01W56ME10
      Text in Illustration
      *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
      0.50 mm (0.0197 in.)

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

    3. A01W2ARE07
      Text in Illustration
      *a Overall Length

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

      Standard Overall Length
      103.92 mm (4.09 in.)
      Minimum Overall Length
      103.42 mm (4.07 in.)

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

  4. INSPECT EXHAUST VALVE


    1. A01W5FT

      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 valve stem diameter is not as specified, check the exhaust valve guide bush oil clearance.

    2. A01VZUWE12
      Text in Illustration
      *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
      0.50 mm (0.0197 in.)

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

    3. A01VZJ9E07
      Text in Illustration
      *a Overall Length

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

      Standard Overall Length
      112.91 mm (4.45 in.)
      Minimum Overall Length
      112.41 mm (4.43 in.)

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

  5. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A01W4TZ

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

  6. INSPECT INTAKE VALVE SEAT


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

    2. A01W4WEE11
      Text in Illustration
      *a Width

      Lightly press the valve face against the intake valve seat.

      Tech Tips

      Do not rotate the intake valve while pressing it.

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


      1. If Prussian blue appears 360° around the entire intake valve face, the valve face is concentric. If not, replace the intake valve.

      2. If Prussian blue appears 360° 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 1.0 to 1.4 mm (0.0394 to 0.0551 in.).

  7. INSPECT EXHAUST VALVE SEAT


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

    2. A01W1F8E09
      Text in Illustration
      *a Width

      Lightly press the valve face against the exhaust valve seat.

      Tech Tips

      Do not rotate the exhaust valve while pressing it.

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


      1. If Prussian blue appears 360° around the entire exhaust valve face, the valve face is concentric. If not, replace the exhaust valve.

      2. If Prussian blue appears 360° 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 1.2 to 1.6 mm (0.0472 to 0.0630 in.).