CYLINDER HEAD INSPECTION

PROCEDURE


  1. INSPECT CYLINDER HEAD FOR FLATNESS


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

      A01VLJZE01
      Text in Illustration
      *a Cylinder Block Side
      *b Intake Manifold Side
      *c Exhaust Manifold Side
      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. A01VG04

      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. A01VLT4E08
      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. A01VHIC

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

    2. A01VM1JE09
      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. A01VHO4

      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. A01VL2YE04
      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. A01VHIC

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

    2. A01VIN6E09
      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. A01VDZH

      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. A01VHMPE13
      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. A01VM1C

      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 OUTER COMPRESSION SPRING

    A01VKDDE01

    Tech Tips

    Type A and Type B can be distinguished by the shape of the outer compression spring.

    Type Outer Compression Spring Shape
    A Straight
    B Taper
    *A Type A
    *B Type B
    *1 No. 1 Valve Rocker Arm Sub-assembly
    *2 Valve Spring Retainer
    *3 Outer Compression Spring
    *4 Valve Lash Adjuster Assembly

    1. Type A:


      1. A01VHGY

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

        Free length
        51.19 mm (2.0154 in.)
        If the free length is not as specified, replace the outer compression spring.
      2. A01VINIE04
        Text in Illustration
        *a Deviation

        Using a steel square and vernier caliper, measure the deviation of the outer compression spring.

        Maximum deviation
        1.8 mm (0.0709 in.)

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

    2. Type B:


      1. A01VJC4

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

        Free length
        57.49 mm (2.2634 in.)
        If the free length is not as specified, replace the outer compression spring.
      2. A01VKA3E02
        Text in Illustration
        *a Deviation

        Using a steel square and feeler gauge, measure the deviation of the outer compression spring as shown in the illustration.

        Maximum deviation
        1.75 mm (0.0689 in.)
        Maximum angle
        2°

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