CYLINDER HEAD INSPECTION


  1. INSPECT CYLINDER HEAD FOR FLATNESS


    1. A0040QFE09
      Text in Illustration
      *a Cylinder Block Sub-assembly Side
      *b Intake Manifold Side
      *c Exhaust Manifold Side

      Using a precision straightedge and feeler gauge, check the surfaces which contact the cylinder block sub-assembly and manifolds for warpage.

      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 side 0.10 mm (0.00394 in.)

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

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. A0040U2

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

      If cracked, replace the cylinder head sub-assembly.

  3. INSPECT VALVE SEATS


    1. A004229E03
      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.

      Tech Tips

      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 camshafts Click here.

    2. A0043IQ

      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 greater than the maximum, replace the camshaft housing sub-assembly. If the thrust surface is damaged, replace the camshaft.

  5. INSPECT CAMSHAFT OIL CLEARANCE


    1. Clean the camshaft bearing caps and camshaft journals.

    2. Place the camshafts on the camshaft housing sub-assembly.

    3. A0041YKE05
      Text in Illustration
      *a Plastigage

      Lay a strip of Plastigage across each of the camshaft journals.

    4. Install the camshaft bearing caps Click here.

      Note

      Do not turn the camshaft.

    5. Remove the camshaft bearing caps Click here.

    6. A004320E05
      Text in Illustration
      *a Plastigage

      Measure the Plastigage at its widest point.

      Standard Oil Clearance
      Item Specified Condition
      Camshaft No. 1 Journal 0.030 to 0.063 mm (0.00118 to 0.00248 in.)
      Camshaft Other Journals 0.035 to 0.072 mm (0.00138 to 0.00283 in.)
      Maximum Oil Clearance
      Item Specified Condition
      Camshaft No. 1 Journal 0.085 mm (0.00335 in.)
      Camshaft Other Journals 0.09 mm (0.00354 in.)

      Note

      Completely remove the Plastigage after the inspection.

      If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head sub-assembly.

  6. INSPECT INNER COMPRESSION SPRING

    A0041L3E01

    Tech Tips

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

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

    1. Type A:


      1. A0040KU

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

        Standard Free Length
        53.87 mm (2.12 in.)

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

      2. A0040SRE07

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

        Maximum Deviation
        1.0 mm (0.0394 in.)

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

    2. Type B:


      1. A0042QY

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

        Standard free length
        51.88 mm (2.042 in.) or 51.90 mm (2.043 in.)

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

      2. A0041NSE04
        Text in Illustration
        *a Deviation

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

        Maximum deviation
        1.4 mm (0.0551 in.)
        Maximum angle
        2°

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

  7. INSPECT INTAKE VALVE


    1. A00414XE03
      Text in Illustration
      *a Overall Length

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

    2. A0040WR

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

      Standard Valve Stem Diameter
      5.470 to 5.485 mm (0.215 to 0.216 in.)

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

    3. A0040ROE03
      Text in Illustration
      *a Margin Thickness

      Using a vernier caliper, measure the intake 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 intake valve.

  8. INSPECT EXHAUST VALVE


    1. A0043Y8E03
      Text in Illustration
      *a Overall Length

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

    2. A0042JC

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

      Standard Valve Stem Diameter
      5.465 to 5.480 mm (0.215 to 0.216 in.)

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

    3. A00434NE03
      Text in Illustration
      *a Margin Thickness

      Using a vernier caliper, measure the exhaust 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 exhaust valve.

  9. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A0041BS

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

      Standard Bushing 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 0.080 mm (0.00315 in.)
      Exhaust 0.085 mm (0.00335 in.)

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