LEXUS LS430 2003 Factory Repair Manual

Fig. 356: Inspecting Exhaust Valve Seat
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Check the valve seating position.
1. Apply a light coat of Prussian blue (or white lead) to the valve face.
2. Lightly press the valve against the seat. Do not rotate valve.
c. Check the valve face and seat for the following:
1. If blue appears 360° around the valve face, the valve seat is concentric. If not, replace the
valve.
2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface
the seat.
3. Check that the seat contact is in the middle of the valve face and has the width below.
Width: 1.0 to 1.4 mm (0.039 to 0.055 in.)

Fig. 357: Checking Valve Seating Position
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If not, correct the exhaust valve seats as follows:
d. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.

Fig. 358: Identifying Cutters Angel Seating Position (To High)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
e. If the seatin
g is too low on the valve face: Use 60° and 45° cutters to correct the seat.

Fig. 359: Identifying Cutters Angel Seating Position (Lo High)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
f. Handrub the valve and valve seat with an abrasive compound.
g. After handrubbing, clean the valve and valve seat.

Fig. 360: Cleaning Valve And Valve Seat
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
17.INSPECT VALVE LIFTER
a. Using a micrometer, measure the lifter diameter at the 12.5 +/- 2.0 mm (0.492 +/- 0.079 in.) from
the top surface.
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If the lifter diameter is not as specified, check the oil clearance.

Fig. 361: Measuring Lifter Diameter Using Micrometer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.000 to 31.016 mm (1.2205 to 1.2211 in.)
If the lifter diameter is not as specified, check the oil clearance.
c. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
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Maximum oil clearance: 0.07 mm (0.0028 in.)
If the oil clearance is
greater than the maximum, replace the lifter. If necessary, replace the cylinder head.

Fig. 362: Measuring Lifter Bore Diameter Of Cylinder Head Using Caliper Gauge
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
18.INSPECT CAMSHAFT
a. Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.08 mm (0.0031 in.)
If the circle runout is
greater than the maximum, replace the camshaft.

Fig. 363: Measuring Circle Runout At Center Journal Using Dial Indicator
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
b. Using a micrometer, measure the cam lobe height.
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Minimum cam lobe height: 42.46 mm (1.6717 in.)
If the cam lobe hei
ght is less than the minimum, replace the camshaft.

Fig. 364: Measuring Cam Lobe Height Using Micrometer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. Inspect the journal diameter of the camshaft.
1. Using a micrometer, measure the journal diameter of the camshaft for the camshaft bearing.
Journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 in.)
If the
journal diameter is not as specified, check the oil clearance.

Fig. 365: Measuring Journal Diameter Of Camshaft Using Micrometer
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. Using a micrometer, measure the journal diameter for the camshaft timing tube.
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If the
journal diameter is not as specified, check the oil clearance.