Valve And Valve Spring

1. Inspect valve stems and valve guides.
   1. Using a caliper gauge, measure the inside diameter of the valve guide.

      Valve guide I.D. 

      Intake/Exhaust: 5.500 - 5.512 mm (0.216 - 0.217 in.)

      Courtesy of KIA MOTORS AMERICA, INC.

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

      Valve stem O.D. 

      Intake: 5.465 - 5.480 mm (0.2151 - 0.2157 in.)

      Exhaust: 5.458 - 5.470 mm (0.2149 - 0.2153 in.)

      Courtesy 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 (0.0008 - 0.0018 in.)

      Exhaust: 0.030 - 0.054 mm (0.0012 - 0.0021 in.)

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

      If the valve face is worn, replace the valve.

   3. Check the valve head margin thickness.

      If the margin thickness is below specification, replace the valve.

      Margin 

      [Standard]

      Intake: 1.0 mm (0.0394 in.)

      Exhaust: 1.1 mm (0.0433 in.)

      Courtesy of KIA MOTORS AMERICA, INC.

   4. Check the valve length.

      Length 

      Intake: 105.27 mm (4.1445 in.)

      Exhaust: 105.50 mm (4.1535 in.)

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

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

3. Inspect valve seats

   Check the valve seat for evidence of overheating and improper contact with the valve face.

   If the valve seat is worn, replace cylinder head.

   Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace cylinder head. Recondition the valve seat with a valve seat grinder or cutter. The valve seat contact width should be within specifications and centered on the valve face.

4. Inspect valve springs.
   1. Using a steel square, measure the out-of-square of the valve spring.
   2. Using vernier calipers, measure the free length of the valve spring.

Valve spring 

[Standard]

Free height: 46.2 mm (1.8188 in)

Out-of-square: 1.5°

Courtesy of KIA MOTORS AMERICA, INC.