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 converter sub-assembly (TWC: Front Catalyst).

      B004J0TC03
      *a Cylinder Head Lower Side *b Intake Manifold Side
      *c Exhaust Manifold Converter Sub-assembly (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 converter sub-assembly (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. B004L9A

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

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

  2. INSPECT COMPRESSION SPRING


    1. B004IDO

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

      Standard Free Length
      47.38 mm (1.87 in.)

      Tech Tips

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

    2. B004NY1C03
      *a Deviation
      *b 30 mm (1.18 in.)

      Using a steel square, measure the deviation of the compression spring at the position shown in the illustration.

      Maximum Deviation
      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. B004NQP

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

      Standard Valve Stem Diameter
      5.470 mm to 5.485 mm (0.21535 to 0.21594 in.)

      Tech Tips

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

    2. B004K8RC03
      *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
      0.50 mm (0.0197 in.)

      Tech Tips

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

    3. B004J0AC03
      *a Overall Length

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

      Standard Overall Length
      103.92 mm (4.09 in.)
      Minimum Overall Length
      103.42 mm (4.07 in.)

      Tech Tips

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

  4. INSPECT EXHAUST VALVE


    1. B004NC2

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

      Standard Valve Stem Diameter
      5.465 mm to 5.480 mm (0.21516 to 0.21575 in.)

      Tech Tips

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

    2. B004KPTC05
      *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
      0.50 mm (0.0197 in.)

      Tech Tips

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

    3. B004NFKC03
      *a Overall Length

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

      Standard Overall Length
      112.91 mm (4.45 in.)
      Minimum Overall Length
      112.41 mm (4.43 in.)

      Tech Tips

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

  5. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. B004ML8

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

      Standard Bush Inside Diameter
      5.510 to 5.530 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 0.08 mm (0.00315 in.)
      Exhaust 0.10 mm (0.00394 in.)

      Tech Tips

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

  6. INSPECT INTAKE VALVE SEAT


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

    2. B004JRXC05
      *a Width

      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 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. 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 and 1.4 mm (0.0394 and 0.0551 in.)

  7. INSPECT EXHAUST VALVE SEAT


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

    2. B004KP9C02
      *a Width

      Lightly press the valve face against the exhaust valve seat.

      Tech Tips

      Do not rotate the exhaust 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. 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
        1.2 and 1.6 mm (0.0472 and 0.0630 in.)

  8. INSPECT CAMSHAFT THRUST CLEARANCE


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

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

    3. Install the camshaft bearing caps.

      Click here

    4. Install the camshaft housing sub-assembly.

      Click here

    5. B004KOC

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

      Standard Thrust Clearance
      Item Specified Condition
      Intake 0.060 to 0.155 mm (0.00236 to 0.00610 in.)
      Exhaust 0.060 to 0.155 mm (0.00236 to 0.00610 in.)
      Maximum Thrust Clearance
      Item Specified Condition
      Intake 0.170 mm (0.00669 in.)
      Exhaust 0.170 mm (0.00669 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.