Inspect Cylinder Head For Cracks; Clean Valves; Inspect Valve Stems And Guide Bushings - Toyota 22R-E Service Manual

ENGINE – ENGINE MECHANICAL

7. INSPECT CYLINDER HEAD FOR CRACKS

Using a dye penetrant, check the combustion cham–
bers, intake and exhaust ports, head surface and the
top of the head for cracks.
If a crack is found, replace the head.

8. CLEAN VALVES

(a) Using a gasket scraper, chip off any carbon from the
valve head.
(b) Using a wire brush, thoroughly clean the valve.

9. INSPECT VALVE STEMS AND GUIDE BUSHINGS

(a) Using a caliper gauge, measure the inside diameter of
the valve guide bushing.
Standard inside diameter: 8.01 – 8.03 mm
(0.3154 – 0.3161 in.)
(b) Using a micrometer, measure the diameter of the
valve stem.
Standard valve stem diameter:
Intake 7.970 – 7.985 mm
(0.3138 – 0.3144 in.)
Exhaust 7.965 – 7.980 mm
(0.3136 – 0.3142 in.)
(c) Subtract the valve stem diameter measurement from
the valve guide bushing diameter measurement.
Standard oil clearance:
Intake 0.025 – 0.060 mm
(0.0010 – 0.0024 in.)
Exhaust 0.030 – 0.650 mm
(0.0012 – 0.0026 in.)
Maximum stem oil clearance:
Intake 0.08 mm (0.0031 in.)
Exhaust 0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the
valve and guide bushing.
EG1–23