CYLINDER HEAD INSPECTION


  1. INSPECT CYLINDER HEAD FOR FLATNESS


    1. A011BSTE04
      Text in Illustration
      *a Cylinder Block Side
      *b Intake Manifold Side
      *c Exhaust Manifold Side

      Using a precision straightedge and a feeler gauge, measure the surfaces that contact the cylinder block and the manifolds for warpage.

      Maximum Warpage
      Item Specified Condition
      Cylinder block side 0.05 mm (0.0020 in.)
      Intake manifold side 0.10 mm (0.0039 in.)
      Exhaust manifold side 0.10 mm (0.0039 in.)

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

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. A0119S4

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

      If cracked, replace the cylinder head.

  3. INSPECT VALVE SEATS


    1. A0118R9E03
      Text in Illustration
      *a 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 according to the following procedure:


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

      2. If Prussian blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.

      3. Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.0 and 1.4 mm (0.0394 to 0.0551 in.).

  4. INSPECT INTAKE VALVE


    1. A01176V

      Using a gasket scraper and wire brush, scrape off any carbon on the valve head.

    2. A01188EE03
      Text in Illustration
      *a Overall Length

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

      Standard overall length
      103.35 mm (4.0689 in.)
      Minimum margin thickness
      102.85 mm (4.0492 in.)

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

    3. A01190G

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

      Valve stem diameter
      5.470 to 5.485 mm (0.21535 to 0.21594 in.)

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

    4. A0119Z1E03
      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
      0.5 mm (0.0197 in.)

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

  5. INSPECT EXHAUST VALVE


    1. A01176V

      Using a gasket scraper and wire brush, scrape off any carbon on the valve head.

    2. A0117C0E03
      Text in Illustration
      *a Overall Length

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

      Standard overall length
      104.5 mm (4.114 in.)
      Minimum overall length
      104.0 mm (4.0945 in.)

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

    3. A011AFG

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

      Valve stem diameter
      5.465 to 5.480 mm (0.21516 to 0.21575 in.)

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

    4. A011BMEE03
      Text in Illustration
      *a Margin Thickness

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

      Standard margin thickness
      1.15 mm (0.0453 in.)
      Minimum margin thickness
      0.65 mm (0.0255 in.)

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

  6. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A011AS6

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

      Bushing inside diameter
      5.51 to 5.53 mm (0.2169 to 0.2177 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 greater than the maximum, replace the valve and guide bush.

  7. INSPECT COMPRESSION SPRING


    1. A01185X

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

      Free length
      51.19 mm (2.0154 in.)

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

    2. A0119KNE09
      Text in Illustration
      *a Deviation

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

      Maximum deviation
      1.8 mm (0.0709 in.)

      If the deviation is greater than the maximum, replace the valve spring.