Valve and Valve Spring

WARNING: This page is about a different variant/trim than selected.

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.)
  
  Fig 1: Measuring Inside Diameter Of Valve Guide
  Courtesy of HYUNDAI MOTOR AMERICA
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.)
  
  Fig 2: Measuring Diameter Of Valve Stem
  Courtesy of HYUNDAI MOTOR AMERICA
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.)
  
  [Limit]
  
  Intake: 0.070 mm (0.00275 in.)
  
  Exhaust: 0.090 mm (0.00354 in.)
  
  If the clearance is greater than maximum, replace the valve or cylinder head.
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: 1.56 ~ 1.86 mm (0.0614 ~ 0.0732 in.)
  
  Exhaust: 1.89 ~ 2.19 mm (0.0744 ~ 0.0862 in.)
  
  Fig 3: Checking Valve Head Margin Thickness
  Courtesy of HYUNDAI MOTOR AMERICA
  
  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.
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.
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°
  
  Fig 4: Measuring Free Length Of Valve Spring
  Courtesy of HYUNDAI MOTOR AMERICA
  
  If the free length is not as specified, replace the valve spring.