LEXUS GS400 2000 Service Repair Manual

A02718
A02815
A02688
EM±46
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
1400 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(f) Measure the Plastigage at its widest point.
Standard oil clearance:
0.035 ± 0.072 mm (0.0014 ± 0.0028 in.)
Maximum oil clearance:
0.10 mm (0.0039 in.)
If the oil clearance is greater than maximum, replace the cam-
shaft. If necessary, replace the bearing caps and cylinder head
as a set.
(g) Completely remove the Plastigage.
14. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Install the camshafts. (See page EM±52)
(b) Using a dial indicator, measure the thrust clearance while
moving the camshaft back and forth.
Standard thrust clearance:
0.080 ± 0.190 mm (0.0031 ± 0.0075 in.)
Maximum thrust clearance:
0.30 mm (0.0118 in.)
If the thrust clearance is greater than maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
15. INSPECT VALVE LIFTERS AND LIFTER BORES
(a) Using a caliper gauge, measure the lifter bore diameter
of the cylinder head.
Lifter bore diameter:
31.000 ± 31.016 mm (1.2205 ± 1.2211 in.)
(b) Using a micrometer, measure the lifter diameter.
Lifter diameter:
30.966 ± 30.976 mm (1.2191 ± 1.2195 in.)
(c) Subtract the lifter diameter measurement from the lifter
bore diameter measurement.
Standard oil clearance:
0.024 ± 0.050 mm (0.0009 ± 0.0020 in.)
Maximum oil clearance:
0.07 mm (0.0028 in.)
If the oil clearance is greater than maximum, replace the lifter.
If necessary, replace the cylinder head.

A02830
A02829
A02831
A02828
About
50 mm
Compressed
Thread
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±47
1401 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
16. INSPECT AIR INTAKE CHAMBER
Using a precision straight edge and feeler gauge, measure the
surfaces contacting the intake manifold for warpage.
Maximum warpage: 0.15 mm (0.0059 in.)
If warpage is greater than maximum, replace the chamber.
17. INSPECT INTAKE MANIFOLD
Using a precision straight edge and feeler gauge, measure the
surfaces contacting the cylinder head and air intake chamber
for warpage.
Maximum warpage: 0.15 mm (0.0059 in.)
If warpage is greater than maximum, replace the manifold.
18. INSPECT EXHAUST MANIFOLD
Using a precision straight edge and feeler gauge, measure the
surfaces contacting the cylinder head for warpage.
Maximum warpage: 0.50 mm (0.0196 in.)
If warpage is greater than maximum, replace the manifold.
19. INSPECT CYLINDER HEAD BOLTS
Using a vernier caliper, measure the thread outside diameter of
the bolt.
Standard outside diameter:
10.8 ± 11.0 mm (0.425 ± 0.433 in.)
Minimum outside diameter:
10.7 mm (0.421 in.)
If the diameter is less than minimum, replace the bolt.

EM0DD±03
A02689SST
A02688
Bushing bore diameter
mm (in.)
10.985 ± 11.006 mm
(0.4325 ± 0.4333 in.)
11.035 ± 11.056 mm
(0.4344 ± 0.4353 in.)Both intake and exhaust
Bushing
size
Use STD
Use O/S
0.05
A02744
SST
P04791
IntakeExhaust
38.5 mm
(1.516 in.)40.5 mm
(1.594 in.) EM±48
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
1402 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REPLACEMENT
REPLACE VALVE GUIDE BUSHINGS
(a) Using SST and a hammer, tap out the guide bushing.
SST 09201±10000 (09201±01060),
09950±70010 (09951±07100)
(b) Using a caliper gauge, measure the bushing bore diame-
ter of the cylinder head.
(c) Select a new guide bushing (STD or O/S 0.05).
If the bushing bore diameter of the cylinder head is greater than
11.006 mm (0.4333 in.), machine the bushing bore to the follow-
ing dimension:
11.035 ± 11.056 mm (0.4344 ± 0.4353 in.)
If the bushing bore diameter of the cylinder head is greater than
11.056 mm (0.4353 in.), replace the cylinder head.
(d) Using SST and a hammer, tap in a new guide bushing to
the specified protrusion height.
SST 09201±10000 (09201±01060),
09950±70010 (09951±07100)
Protrusion height:
Intake12.3 ± 12.7 mm (0.484 ± 0.500 in.)
Exhaust11.4 ± 11.8 mm (0.449 ± 0.465 in.)
HINT:
Different bushings are used for the intake and exhaust.

A02687
Sharp
6 mm
Reamer
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±49
1403 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Using a sharp 6 mm reamer, ream the guide bushing to
obtain the standard specified clearance (See page
EM±40) between the guide bushing and valve stem.

EM0D2±04
A11131
(d) (g)
(f)
(e) (b)
(c)
A11130
(h)(i)
(j)
(k)
A11129
(o)
(n)
(o)
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
EM±5
1359 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
VALVE CLEARANCE
ADJUSTMENT
HINT:
Inspect and adjust the valve clearance when the engine is cold.
1. REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
2. DRAIN ENGINE COOLANT
3. REMOVE INTAKE AIR RESONATOR
4. REMOVE THROTTLE BODY AND INTAKE AIR
CONNECTOR ASSEMBLY
(a) Disconnect the accelerator cable from the throttle body.
(b) Disconnect the engine wire clamp from the clamp bracket
of the throttle body.
(c) Disconnect the engine wire from the clamp on the throttle
body bracket.
(d) Disconnect the accelerator pedal position sensor con-
nector.
(e) Disconnect the throttle control motor connector.
(f) Disconnect the throttle position sensor connector.
(g) Disconnect the air assist hose from the intake air connec-
tor.
(h) Disconnect the PCV hose from the intake air connector.
(i) Disconnect the VSV connector for EVAP.
(j) Disconnect the EVAP hose (from charcoal canister) from
the VSV for EVAP.
(k) Disconnect the vacuum hose (from No.2 vacuum pipe)
from the No.1 vacuum pipe.
(l) Remove the 2 nuts holding the throttle body bracket to the
cylinder head.
(m) Remove the 4 bolts and 2 nuts holding the intake air con-
nector to the air intake chamber.
(n) Disconnect the vacuum hose (from actuator for ACIS)
from the No.1 vacuum pipe.
(o) Disconnect the 2 water bypass hoses from the throttle
body, and remove the throttle body together with the in-
take air connector and gasket.

A02638
A02651
A02664
EX
IN135
24
135
24 1 1
EM±6
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
1360 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. REMOVE NO.3 TIMING BELT COVER
Using a 5 mm hexagon wrench, remove the 4 bolts, oil filler cap,
timing belt cover and gasket.
6. REMOVE IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±7)
7. REMOVE SPARK PLUGS
8. DISCONNECT ENGINE WIRE FROM CYLINDER HEAD
COVERS
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 º0º of the No.1 timing belt cover.
NOTICE:
Always turn the crankshaft clockwise.
(b) Check that the timing marks of the camshaft timing pul-
leys are aligned with the timing marks of the No.4 timing
belt cover.
If not, turn the crankshaft 1 revolution (360°).
11. INSPECT VALVE CLEARANCE
(a) Check only those valves indicated in the illustration.

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

Record the valve clearance measurements of those
that are out of specification. They will be used later
to determine the required replacement adjusting
shim.
Valve clearance (Cold):
Intake0.15 ± 0.25 mm(0.006 ± 0.010 in.)
Exhaust0.25 ± 0.35 mm (0.010 ± 0.014 in.)
(b) Turn the crankshaft pulley 1 revolution (360°), and align
the groove with the timing mark º0º of the No.1 timing belt
cover.

A02665
EX
IN
35 24
35 24
66
66
P02094
Upward
Cam Lobe
Notch
P12860
EX Side
IN SideSST (B)
P12294
SST (A)
P11926
SST (A) SST (B)
7
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
EM±7
1361 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(c) Check only the valves indicated as shown. Measure the
valve clearance. (See procedure in step (a))
12. ADJUST VALVE CLEARANCE
(a) Remove the adjusting shim.

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

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

Insert SST (B) gently from the inside as shown in the
illustration.

Using SST (A), hold the camshaft as shown in the
illustration.
SST 09248±55040 (09248±05410)

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:

Apply SST (B) at slight angle on the side marked with º7º
or º9º, at the position shown in the illustration.

A02666
SST (A) SST (B)
9
P10901
SST (B)
Magnetic Finger
EM0494
P11925
SST (A)
SST (B) EM±8
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
1362 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

When the adjusting shim of the No.1 intake side replace,
remove the No.2 or No.3 camshaft bearing cap, and in-
sert SST as shown in the illustration.

Using a small screwdriver and a magnetic finger, remove
the adjusting shim.
(b) Determine the replacement adjusting shim size according
to the following formula or Charts:

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

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

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.).
(c) Install a new adjusting shim.

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

Press down the valve lifter with SST (A), and re-
move SST (B).
SST 09248±55040
13. REINSTALL CYLINDER HEAD COVERS
(See page EM±52)
14. RECONNECT ENGINE WIRE TO CYLINDER HEAD
COVERS

± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
EM±9
1363 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
15. REINSTALL SPARK PLUGS
16. REINSTALL IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±9)
17. REINSTALL NO.3 TIMING BELT COVER
(a) Install the gasket to the timing belt cover.
(b) Using a 5 mm hexagon wrench, install the timing belt cov-
er with the 4 bolts.
Torque: 8.0 N´m (80 kgf´cm, 71 in.´lbf)
(c) Install the oil filler cap.
18. REINSTALL THROTTLE BODY AND INTAKE AIR CON-
NECTOR ASSEMBLY
(a) Install a new gasket to the air intake chamber.
(b) Place the throttle body together with the intake air con-
nector on the cylinder head.
(c) Connect the vacuum hose (from actuator for ACIS) to the
No.1 vacuum pipe.
(d) Connect the 2 water bypass hoses to the throttle body.
(e) Install the 4 bolts and 2 nuts holding the intake air connec-
tor to the air intake chamber.
Torque: 28 N´m (280 kgf´cm, 21 ft´lbf)
(f) Install the 2 nuts holding the throttle body bracket to the
cylinder head.
Torque: 21 N´m (210 kgf´cm, 15 ft´lbf)
(g) Connect the air assist hose to the intake air connector.
(h) Install the PCV hose to the intake air connector.
(i) Install the EVAP hose (from charcoal canister) to the VSV
for EVAP.
(j) Install the vacuum hose (from No.2 vacuum pipe) to the
No.1 vacuum pipe.
(k) Install the throttle position sensor connector.
(l) Install the accelerator pedal position sensor connector.
(m) Install the throttle control motor connector.
(n) Install the VSV connector for EVAP.
(o) Secure the engine wire with the clamp on the throttle body
bracket.
(p) Install the engine wire clamp with the clamp bracket of the
throttle body.
(q) Connect the accelerator cable to the throttle body.
19. REINSTALL INTAKE AIR RESONATOR
20. REINSTALL ENGINE COVER
Install the engine cover with the 4 nuts.
21. REFILL WITH ENGINE COOLANT
22. START ENGINE AND CHECK FOR LEAKS

V00719
Adjusting Shim Selection Chart (Intake)
Intake valve clearance (Cold):
0.15 ± 0.25 mm (0.006 ± 0.010 in.)
EXAMPLE: The 2.800 mm (0.1102 in.) shim is installed, and
the measured clearance is 0.450 mm (0.0177 in.).
Replace the 2.800 mm (0.1102 in.) shim with a new No.12 shim.New shim thickness mm (in.)
Shim
No. ThicknessThickness Shim
No.
HINT: New shims have the thickness
in millimeters imprinted on the face.
Installed Shim Thickness
mm (in.)
Measured Clearance
mm (in.)
EM±10
± ENGINE MECHANICAL (2JZ±GE)VALVE CLEARANCE
1364 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)