Valve Guide: Testing and Inspection

1. Clean valve guide bushings Using a valve guide bushing brush and solvent, clean all the guide bushings.






2. Using a gasket scraper, chip off any carbon from the valve head.
3. Using a wire brush, thoroughly clean the valve.






4. Using a caliper gauge, measure the inside diameter of the guide bushing.
Valve guide bushing standard diameter: 6.010-6.030 mm (0.2366-0.2374 in).






5. Using a micrometer, measure the diameter of the valve stem.
Valve stem standard diameter:
Intake: 5.970-5.985 mm (0.2350-0.2356 in).
Exhaust: 5.965-5.980 mm (0.2348-0.2354 in).
6. Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Standard oil clearance:
Intake: 0.025-0.060 mm (0.0010-0.0024 in).
Exhaust: 0.030-0.065 mm (0.0012-0.0026 in).
Maximum oil clearance:
Intake: 0.080 mm (0.0031 in).
Exhaust: 0.100 mm (0.0039 inch.).
7. If the clearance is greater than maximum, replace the valve and/or the guide bushing.