Valve Guides
Check the valve stem-to-guide clearance. If the clearance exceeds the service limit, replace the valve guide with a new oversize guide.
Valve stem-to-guide clearance
Standard value
Intake : 0.02-0.05 mm (0.0009-0.0020 in.)
Exhaust: 0.035-0.065 mm (0.0014-0.0026 in.)
Service limit
Intake : 0.10 mm (0.0039 in.)
Exhaust : 0.15 mm (0.0059 in.)
Scheme 369
Scheme 370
- Replace the valve stem if it is worn (stepped, worn or damaged). Also replace it if the stem end (the surface contacting the auto-lash adjuster) is recessed.
- Check the valve face contact area, and recondition or replace as necessary.
- 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 side : 1.0 mm (0.0394 in.) Exhaust side : 1.3 mm (0.0512 in.) Service limit Intake side : 0.5 mm (0.0197 in.) Exhaust side : 0.8 mm (0.0315 in.)
