LEMON Manuals: Even more car manuals for everyone
Home >> Kia >> 2020 >> Optima EX Premium >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 48 (Cylinder Head Assembly - 2.4L (Except HEV)) >> Cylinder Head >> Repair Procedures >> Inspection >> Valve And Valve Spring

Valve And Valve Spring

WARNING: This page is about a different variant/trim than selected.
  1. Inspect valve stems and valve guides.
    1. Using a caliper gauge, measure the inside diameter of the valve guide.

      Valve guide inner diameter 

      Intake/Exhaust:

      5.500 - 5.512 mm (0.21654 - 0.21701 in.)

      G12932381Courtesy of KIA MOTORS AMERICA, INC.
    2. Using a micrometer, measure the diameter of the valve stem.

      Valve stem outer diameter 

      Intake: 5.465 - 5.480 mm (0.21516 - 0.21575 in.)

      Exhaust: 5.458 - 5.470 mm (0.214988 - 0.21535 in.)

      G12932382Courtesy of KIA MOTORS AMERICA, INC.
    3. Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.

      Valve stem-to-guide clearance 

      [Standard]

      Intake: 0.020 - 0.047 mm (0.00078 - 0.00185 in.)

      Exhaust: 0.030 - 0.054 mm (0.00118 - 0.00212 in.)

      If the clearance is greater than maximum, replace the valve or cylinder head.

  2. Inspect the valves.
    1. Check the valve is ground to the correct valve face angle.
    2. Check that the surface of the valve for wear.

      If the valve face is worn, replace the valve.

    3. Check the valve head margin thickness.

      Valve head thickness (Margin) 

      [Standard]

      Intake: 1.02 mm (0.0401 in.)

      Exhaust: 1.09 mm (0.0429 in.)

      G12932383Courtesy of KIA MOTORS AMERICA, INC.

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

    4. Check the valve length.

      Valve length 

      [Standard]

      Intake: 113.18 mm (4.4559 in.)

      Exhaust: 105.84 mm (4.1669 in.)

      [Limit]

      Intake: 112.93 mm (4.4461 in.)

      Exhaust: 105.59 mm (4.1571 in.)

    5. Check the surface of the valve stem tip for wear.

      If the valve stem tip is worn, replace the valve.

  3. Inspect the valve seats
    1. Check the valve seat for evidence of overheating and improper contact with the valve face. Replace the cylinder head if necessary.
    2. Check the valve guide for wear. If the valve guide is worn, replace the cylinder head.
  4. Inspect the valve springs.
    1. Using a steel square, measure the out-of-square of the valve spring.
    2. Using a vernier calipers, measure the free length of the valve spring.

      Valve spring 

      [Standard]

      Free height: 47.44 mm (1.8677 in.)

      Out-of-square: Less than 1.5°

      G12932384Courtesy of KIA MOTORS AMERICA, INC.

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

scientia non olet · About LEMON Manuals