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 (TWC: Front Catalyst).

      B006WUKC01
      *a Bottom Side *b Intake Manifold Side
      *c Exhaust Manifold (TWC: Front Catalyst) Side - -
      Maximum Warpage
      Item Specified Condition
      Bottom side 0.05 mm (0.00197 in.)
      Intake manifold side 0.10 mm (0.00394 in.)
      Exhaust manifold (TWC: Front Catalyst) side 0.10 mm (0.00394 in.)

      Tech Tips

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

    2. B0071J2

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

      Tech Tips

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

  2. INSPECT COMPRESSION SPRING


    1. Intake Side:


      1. B0071B9

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

        Standard Free Length
        58.61 mm (2.32 in.)

        Note

        Compression springs come in 2 different lengths. Make sure all compression springs are the same length when replacing them.

      2. B0071NVC01
        *a Deviation
        *b 37 mm (1.46 in.)

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

        Maximum Deviation (Reference)
        1.0 mm (0.0394 in.)

        Tech Tips

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

    2. Exhaust Side:


      1. B0071B9

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

        Standard Free Length
        61.08 mm (2.40 in.)

        Note

        Compression springs come in 2 different lengths. Make sure all compression springs are the same length when replacing them.

      2. B0071NVC01
        *a Deviation
        *b 38 mm (1.50 in.)

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

        Maximum Deviation (Reference)
        1.0 mm (0.0394 in.)

        Tech Tips

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

  3. INSPECT INTAKE VALVE


    1. B006YKD

      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.)

      Tech Tips

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

    2. B006ZKUC01
      *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.)

      Tech Tips

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

    3. B0070EQC01
      *a Overall Length

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

      Standard Overall Length
      104.45 mm (4.11 in.)
      Minimum Overall Length
      103.95 mm (4.09 in.)

      Tech Tips

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

  4. INSPECT EXHAUST VALVE


    1. B00703U

      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.)

      Tech Tips

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

    2. B0071PWC01
      *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.)

      Tech Tips

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

    3. B0071QIC01
      *a Overall Length

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

      Standard Overall Length
      108.7 mm (4.28 in.)
      Minimum Overall Length
      108.2 mm (4.26 in.)

      Tech Tips

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

  5. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. B0071OZ

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

      Standard Valve Guide Bush Inside Diameter
      5.51 to 5.53 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 Side 0.025 to 0.060 mm (0.000984 to 0.00236 in.)
      Exhaust Side 0.030 to 0.065 mm (0.00118 to 0.00256 in.)
      Maximum Oil Clearance
      Item Specified Condition
      Intake Side 0.080 mm (0.00315 in.)
      Exhaust Side 0.10 mm (0.00394 in.)

      Tech Tips


      • Oil clearance = Valve guide bush inside - Valve stem diameter

      • 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. B0071D0C01
      *a Width

      Lightly press the valve face against the intake valve seat.

      Note

      Do not rotate the 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.

        Tech Tips

        If the valve face is not concentric, 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.

        Tech Tips

        If the valve face is not concentric, resurface the intake valve seat.

      3. Measure the width of the contact area of the intake valve seat and valve face.

        Standard Width
        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. B006XG0C01
      *a Width

      Lightly press the valve face against the exhaust valve seat.

      Note

      Do not rotate the 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.

        Tech Tips

        If the valve face is not concentric, 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.

        Tech Tips

        If the valve face is not concentric, resurface the exhaust valve seat.

      3. Measure the width of the contact area of the exhaust valve seat and valve face.

        Standard Width
        1.3 to 1.7 mm (0.0512 to 0.0669 in.)

  8. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Clean the No. 1 camshaft bearing cap, No. 2 camshaft bearing cap, 2 No. 3 camshaft bearing caps, No. 4 camshaft bearing cap, camshaft housing sub-assembly and camshaft journals.

    2. Place the camshaft and No. 2 camshaft on the camshaft housing sub-assembly on the cylinder head sub-assembly.

    3. Install the camshaft bearing caps.

      Click here

    4. Install the camshaft housing sub-assembly.

      Click here

    5. B0071U3

      Using a dial indicator, measure the thrust clearance while moving the camshaft and No. 2 camshaft back and forth.

      Standard Thrust Clearance
      Item Specified Condition
      Camshaft 0.04 to 0.17 mm (0.00157 to 0.00669 in.)
      No. 2 Camshaft 0.04 to 0.17 mm (0.00157 to 0.00669 in.)
      Maximum Thrust Clearance
      Item Specified Condition
      Camshaft 0.22 mm (0.00866 in.)
      No. 2 Camshaft 0.22 mm (0.00866 in.)

      Tech Tips

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