Valve And Valve Spring

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.)

   Fig 1: Measuring Inside Diameter Of Valve Guide Using Caliper Gauge

   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.)

   Fig 2: Measuring Diameter Of Valve Stem Using Micrometer

   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.)

   [Limit]

   Intake: 0.07 mm (0.0027 in.)

   Exhaust: 0.09 mm (0.0035 in.)

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.

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

   Margin 

   [Standard]

   Intake: 1.56 ~ 1.86 mm (0.06142 ~ 0.07323 in.)

   Exhaust: 1.73 ~ 2.03 mm (0.06811 ~ 0.07992 in.)

   Fig 3: Identifying Valve Head Margin Thickness

   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.

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.

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: 43.86 mm (1.7267 in.)

   Out-of-square: 1.5°

   Fig 4: Measuring Free Length Of Valve Spring Using Vernier Calipers

   Courtesy of KIA MOTORS AMERICA, INC.