Cylinder Head: Inspection: Valve

1. Replace the valve if its stem is bent, worn or damaged. Also replace it if the stem end (the surface contacting the hydraulic-lash adjuster) is hollowed out.
2. Check the valve face contact area, and recondition or replace as necessary.
   Fig 1: Checking Valve

   Courtesy of HYUNDAI MOTOR CO.
3. Replace the valve if the width of the margin (thickness of the valve head) is less than the minimum specified.

Valve margin 

Standard value

Intake : 1.0mm(0.0394 in.)

Exhaust : 1.3mm(0.0512 in.)

Fig 2: Identifying Valve Margin

Courtesy of HYUNDAI MOTOR CO.