Z02413
Z00052
Z00054
44.5°
EM0181
Margin Thickness EM±42
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
1396 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. INSPECT VALVE STEMS AND GUIDE BUSHINGS
(a) Using a caliper gauge, measure the inside diameter of the
guide bushing.
Bushing inside diameter:
6.010 ± 6.030 mm (0.2366 ± 0.2374 in.)
(b) Using a micrometer, measure the diameter of the valve
stem.
Valve stem diameter:
Intake5.970 ± 5.985 mm (0.2350 ± 0.2356 in.)
Exhaust5.965 ± 5.980 mm (0.2348 ± 0.2354 in.)
(c) Subtract the valve stem diameter measurement from the
guide bushing inside diameter measurement.
Standard oil clearance:
Intake0.025 ± 0.060 mm (0.0010 ± 0.0024 in.)
Exhaust0.030 ± 0.065 mm (0.0012 ± 0.0026 in.)
Maximum oil clearance:
Intake0.08 mm (0.0031 in.)
Exhaust0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the valve and
guide bushing. (See page EM±48)
6. INSPECT AND GRIND VALVES
(a) Grind the valve enough to remove pits and carbon.
(b) Check that the valve is ground to the correct valve face
angle.
Valve face angle: 44.5°
(c) Check the valve head margin thickness.
Standard margin thickness:
0.8 ± 1.2 mm (0.031 ± 0.047 in.)
Minimum margin thickness:
0.5 mm (0.020 in.)
If the margin thickness is less than minimum, replace the valve.
