Lexus RX300 (MCU15). Manual — part 430

P18805

A05071

EM0KG–02

A05273

RH EX

RH IN

LH IN

LH EX

3

3

1 1

Front

2 2

6 6

EM–4

–

ENGINE MECHANICAL

VALVE CLEARANCE

LEXUS RX300 (RM785E)

VALVE CLEARANCE

INSPECTION

HINT:
Inspect and adjust the valve clearance when the engine is cold.
1.

REMOVE OUTER COWL TOP PANEL
(See page EM–75)

2.

REMOVE FRONT UPPER SUSPENSION BRACE
(See page EM–75)

3.

REMOVE RH FENDER APRON SEAL

4.

DRAIN ENGINE COOLANT

5.

REMOVE V–BANK COVER

(a)

Using a 5 mm hexagon wrench, remove the 3 nuts.

(b)

Remove the V–bank cover fastener clip and V–bank cov-
er.

6.

REMOVE AIR INTAKE CHAMBER ASSEMBLY
(See page EM–33)

7.

REMOVE IGNITION COILS

8.

DISCONNECT UPPER RADIATOR HOSE FROM
WATER OUTLET

9.

REMOVE CYLINDER HEAD COVERS
(See page EM–33)

10.

SET NO. 1 CYLINDER TO TDC/COMPRESSION

(a)

Turn the crankshaft pulley, and align its groove with the
timing mark ”0” of the No. 1 timing belt cover.

(b)

Check that the valve lifters on the No. 1 (IN and EX) are
loose.

If not, turn the crankshaft 1 revolution (360

°) and align the mark

as above.

11.

INSPECT VALVE CLEARANCE

(a)

Check only those valves indicated in the illustration.

S

Using a feeler gauge, measure the clearance be-
tween the valve lifter and camshaft.

S

Record out of specification valve clearance mea-
surements. They will be used later to determine the
required replacement adjusting shim.

Valve clearance (Cold):
Intake: 0.15 – 0.25 mm (0.006 – 0.010 in.)
Exhaust: 0.25 – 0.35 mm (0.010 – 0.014 in.)

A05272

RH EX

RH IN

LH IN

LH EX

3 3

2 2

Front

5

5

4 4

A05274

RH EX

RH IN

LH IN

LH EX

Front

5 5

4 4

6 6

1 1

P12919

Upward

Notch

–

ENGINE MECHANICAL

VALVE CLEARANCE

EM–5

LEXUS RX300 (RM785E)

(b)

Turn the crankshaft 2/3 of a revolution (240

°), and check

only the valves indicated in the illustration. Measure the
valve clearance. (See procedure step (a))

(c)

Turn the crankshaft a further 2/3 of a revolution (240

°),

and check only the valves indicated in the illustration.
Measure the valve clearance.
(See procedure step (a))

12.

ADJUST VALVE CLEARANCE

(a)

Remove the adjusting shim.

S

Turn the camshaft so that the cam lobe for the valve
to be adjusted faces up.

S

Turn the valve lifter with a screwdriver so that the
notches are perpendicular to the camshaft.

Z09456

Front of No. 1 and No. 2 cylinders:

Others:

SST (A)

SST (A)

SST (B)

SST (B)

P12920

SST (B)

Magnetic Finger

EM0494

EM–6

–

ENGINE MECHANICAL

VALVE CLEARANCE

LEXUS RX300 (RM785E)

S

Using SST (A), press down the valve lifter and place
SST (B) between the camshaft and valve lifter. Re-
move SST (A).

SST

09248–55040 (09248–05410, 09248–05420)

HINT:

S

Apply SST (B) at a slight angle on the side marked with
”9” or ”7”, at the position shown in the illustration.

S

When SST (B) is inserted too deeply, it will get pinched by
the shim. To prevent it from being stuck, insert it gently
from the intake side, at a slight angle.

S

Using a small screwdriver and magnetic finger, remove
the adjusting shim.

(b)

Determine the replacement adjusting shim size according
to these Formula or Charts:

S

Using a micrometer, measure the thickness of the
removed shim.

S

Calculate the thickness of a new shim so the valve
clearance comes within the specified value.

T . . .. Thickness of used shim
A . . .. Measured valve clearance
N . . .. Thickness of new shim
Intake: N = T + (A – 0.20 mm (0.008 in.))
Exhaust: N = T + (A – 0.30 mm (0.012 in.))

S

Select a new shim with a thickness as close as pos-
sible to the calculated values.

HINT:
Shims are available in 17 sizes in increments of 0.050 mm
(0.0020 in.), from 2.500 mm (0.0984 in.) to 3.300 mm (0.1299
in.).

P12979

SST (B)

SST (A)

–

ENGINE MECHANICAL

VALVE CLEARANCE

EM–7

LEXUS RX300 (RM785E)

(c)

Install a new adjusting shim.

S

Place a new adjusting shim on the valve lifter, with
imprinted numbers facing down.

S

Press down the valve lifter with SST (A), and re-
move SST (B).

SST

09248–55040 (09248–05410, 09248–05420)

(d)

Recheck the valve clearance.

13.

REINSTALL CYLINDER HEAD COVERS
(See page EM–60)

14.

CONNECT UPPER RADIATOR HOSE TO WATER
OUTLET

15.

REINSTALL IGNITION COILS

16.

REINSTALL AIR INTAKE CHAMBER ASSEMBLY
(See page EM–60)

17.

INSTALL V–BANK COVER

18.

REFILL WITH ENGINE COOLANT

19.

START ENGINE AND CHECK FOR LEAKS

20.

REINSTALL RH FENDER APRON SEAL

21.

INSTALL FRONT UPPER SUSPENSION BRACE
(See page EM–82)

22.

REINSTALL OUTER COWL TOP PANEL
(See page EM–82)