CYLINDER HEAD INSPECTION


  1. CLEAN CYLINDER HEAD SUB-ASSEMBLY


    1. Using a gasket scraper, remove all the gasket material from the surface of the cylinder head that contacts the cylinder block.

      Note

      Be careful not to scratch the surface of the cylinder head.

    2. Using a soft brush and solvent, thoroughly clean the cylinder head.

    3. A00JZRIE01

      Using a valve guide bushing brush and solvent, clean all the guide bushes.

  2. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. A00JY12E04
      Text in Illustration
      *A Cylinder Block Side
      *B Intake Manifold Side
      *C Exhaust Manifold Side

      Inspect the cylinder head for warpage.


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

        Maximum warpage
        0.15 mm (0.00591 in.)

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

    2. Inspect the cylinder head for cracks.


      1. Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.

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

  3. CLEAN INTAKE VALVE


    1. Using a gasket scraper, chip off any carbon from the valve head.

    2. Using a wire brush, thoroughly clean the valve.

  4. INSPECT INTAKE VALVE


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

      Standard valve stem diameter
      5.970 to 5.985 mm (0.235 to 0.236 in.)

      If the diameter is not as specified, replace the intake valve.

    2. A00JUDTE10
      Text in Illustration
      *1 Valve Face Angle

      Check the valve face angle.


      1. Grind the valve enough to remove any pits and carbon.

      2. Check that the valve is ground to the correct valve face angle.

        Standard valve face angle
        44.5°

        If the result is not as specified, replace the valve.

    3. A00JTZGE06
      Text in Illustration
      *1 Margin Thickness

      Check the valve head margin thickness.

      Standard margin thickness
      1.1 mm (0.0433 in.)
      Minimum margin thickness
      0.8 mm (0.0315 in.)

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

    4. Check the overall valve length.

      Standard overall length
      105.15 to 105.75 mm (4.14 to 4.16 in.)
      Minimum overall length
      104.65 mm (4.12 in.)

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

    5. A00JXFIE01

      Check the surface of the valve stem tip for wear.

      If the valve stem tip is worn, resurface the tip with a grinder or replace the intake valve.

      Note

      Do not grind the valve so it becomes shorter than the minimum overall length.

  5. CLEAN EXHAUST VALVE


    1. Using a gasket scraper, chip off any carbon from the valve head.

    2. Using a wire brush, thoroughly clean the exhaust valve.

  6. INSPECT EXHAUST VALVE


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

      Standard valve stem diameter
      5.960 to 5.975 mm (0.2346 to 0.2352 in.)

      If the diameter is not as specified, replace the valve.

    2. A00JUDTE10
      Text in Illustration
      *1 Valve Face Angle

      Check the valve face angle.


      1. Grind the valve enough to remove any pits and carbon.

      2. Check that the valve is ground to the correct valve face angle.

        Standard valve face angle
        44.5°

        If the result is not as specified, replace the exhaust valve.

    3. A00JTZGE06
      Text in Illustration
      *1 Margin Thickness

      Check the valve head margin thickness.

      Standard margin thickness
      1.2 mm (0.0472 in.)
      Minimum margin thickness
      0.7 mm (0.0276 in.)

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

    4. Check the overall valve length.

      Standard overall length
      105.02 to 105.62 mm (4.13 to 4.16 in.)
      Minimum overall length
      104.52 mm (4.11 in.)

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

    5. A00JXFIE01

      Check the surface of the valve stem tip for wear.

      If the valve stem tip is worn, resurface the tip with a grinder or replace the exhaust valve.

      Note

      Do not grind the valve so it becomes shorter than the minimum overall length.

  7. INSPECT INNER COMPRESSION SPRING


    1. A00JZ2KE05
      Text in Illustration
      *1 Deviation

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

      Maximum deviation
      2.0 mm (0.0787 in.)

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

    2. A00K1IWE03

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

      Standard Free Length
      Item Specified Condition
      w/ DPF 48.4 mm (1.91 in.)
      w/o DPF 46.5 mm (1.83 in.)

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

    3. A00JY3EE01

      Using a spring tester, measure the tension of the valve spring at the specified installed length.

      Standard tension (at 33.1 mm (1.303 in.))
      Item Specified Condition
      w/ DPF 175 to 193 N (17.9 to 19.6 kgf, 39.4 to 43.3 lbf)
      w/o DPF 150 to 165 N (15.3 to 16.9 kgf, 33.7 to 37.0 lbf)

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

  8. INSPECT INTAKE VALVE GUIDE BUSH


    1. A00JU8YE03

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

      Standard valve guide bush inside diameter
      6.01 to 6.03 mm (0.2366 to 0.2374 in.)

    2. Subtract the valve stem diameter measurement (refer to the intake valve inspection procedures above) from the valve guide bush inside diameter measurement.

      Standard oil clearance
      0.025 to 0.060 mm (0.000984 to 0.00236 in.)
      Maximum oil clearance
      0.08 mm (0.00315 in.)

      If the oil clearance is more than the maximum, replace the intake valve and intake valve guide bush.

  9. INSPECT EXHAUST VALVE GUIDE BUSH


    1. A00JV3ZE03

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

      Standard valve guide bush inside diameter
      6.01 to 6.03 mm (0.2366 to 0.2374 in.)

    2. Subtract the valve stem diameter measurement (refer to the exhaust valve inspection procedures above) from the valve guide bush inside diameter measurement.

      Standard oil clearance
      0.035 to 0.070 mm (0.00138 to 0.00276 in.)
      Maximum oil clearance
      0.10 mm (0.00394 in.)

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

  10. INSPECT INTAKE VALVE SEAT


    1. A00JVMME06
      Text in Illustration
      *1 45° Carbide Cutter

      Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the valve seats.

    2. A00JUFOE02
      Text in Illustration
      *1 Width

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

    3. Lightly press the valve face against the valve seat.

      Note

      Do not rotate the valve while pressing the valve against the valve seat.

    4. Check the valve face and valve seat.


      1. 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 1.2 and 1.6 mm (0.0472 and 0.0630 in.).

        If the contact surfaces are not as specified, resurface the valve intake seat. If necessary, replace the intake valve.

      2. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.

        If the contact surfaces are not as specified, resurface the intake valve seat. If necessary, replace the intake valve.

  11. INSPECT EXHAUST VALVE SEAT


    1. A00JUGVE04
      Text in Illustration
      *1 45° Carbide Cutter

      Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the valve seats.

    2. A00JUFOE02
      Text in Illustration
      *1 Width

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

    3. Lightly press the valve face against the valve seat.

      Note

      Do not rotate the valve while pressing the valve against the valve seat.

    4. Check the valve face and valve seat.


      1. 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 1.6 and 2.0 mm (0.0630 and 0.0787 in.)

        If the contact surfaces are not as specified, resurface the exhaust valve seat. If necessary, replace the exhaust valve.

      2. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.

        If the contact surfaces are not as specified, resurface the exhaust valve seat. If necessary, replace the exhaust valve.

  12. INSPECT CAMSHAFT OIL CLEARANCE


    1. Clean the bearing caps and journals.

    2. Check the bearings for flaking and scoring.

      If the bearings are damaged, replace the bearing caps and cylinder head as a set.

    3. Place the camshaft on the cylinder head.

    4. A00JURLE01
      Text in Illustration
      *A Intake Side
      *B Exhaust Side
      *1 Plastigage

      Lay a strip of Plastigage across each of the journals.

    5. A00JYJHE03

      Install the bearing caps.

      Note

      Do not turn the camshaft.

    6. Remove the bearing caps.

    7. A00K1LZE01
      Text in Illustration
      *A Intake Side
      *B Exhaust Side
      *1 Plastigage

      Measure the Plastigage at its widest point.

      Standard oil clearance
      0.025 to 0.062 mm (0.000984 to 0.00244 in.)
      Maximum oil clearance
      0.1 mm (0.00394 in.)

      If the oil clearance is more than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

    8. Completely remove the Plastigage.

    9. Remove the camshaft.

  13. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Install the camshaft.

    2. A00K1J5E01
      Text in Illustration
      *A Intake Side
      *B Exhaust Side

      Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

      Standard thrust clearance
      0.035 to 0.185 mm (0.00138 to 0.0728 in.)
      Maximum thrust clearance
      0.25 mm (0.00984 in.)

      If the thrust clearance is more than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

    3. Remove the camshaft.