Valve Inspection And Measurement

Clean the valves of carbon and oil. Carbon can be removed with a wire brush.

Fig 1: Valve Inspection And Measurement
Courtesy of GENERAL MOTORS COMPANY
Inspect the valves for the following conditions:
1. Inspect the valve faces for burning and cracking (1). If pieces are broken, replace the valve and inspect the corresponding piston and cylinder head area for damage.
2. Inspect the valve for straightness and distortion (2). Distorted valve must be replaced.
3. Inspect the valve stem for wear (3).
4. Inspect the valve key grooves for chipping and wear (5). Replace the valve if chipped or worn.
Measure the valve length (2). Use a slide gauge (1). Refer to Engine Mechanical Specifications to find the permitted values.

Fig 2: Measuring Valve Length Using Slide Gauge
Courtesy of GENERAL MOTORS COMPANY
Measure the valve stem diameter. Use a micrometer gauge (2). Refer to Engine Mechanical Specifications to find the permitted values. Note the measurement results.

Fig 3: Measuring Valve Stem Diameter Using Micrometer Gauge
Courtesy of GENERAL MOTORS COMPANY