2000 LEXUS GS400 intake

A02707
A02711P02145
P02135
P02144
A03796
A02708
EM0580
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±41
1395 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) Clean the cylinder head.
Using a soft brush and solvent, thoroughly clean the cylin-
der head.
3. INSPECT CYLINDER HEAD
(a) Inspect for the flatness.
Using precision straight edge and feeler gauge, measure
the surfaces contacting the cylinder block, intake and ex-
haust manifolds for warpage.
Maximum warpage: 0.10 mm (0.0039 in.)
If warpage is greater than maximum, replace the cylinder head.
(b) Inspect for the cranks.
Using a dye penetrant, check the combustion chamber,
intake ports, exhaust ports and cylinder block surface for
cracks.
If cracked, replace the cylinder head.
4. CLEAN VALVES
(a) Using a gasket scraper, chip off any carbon from the valve
head.
(b) Using a wire brush, thoroughly clean the valve.

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.

EM2534
Overall
Length
EM0255
A02709
45° Carbide Cutter
Z00373
Width
P03966
Width 45°
15°
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±43
1397 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) Check the valve overall length.
Standard overall length:
Intake98.29 ± 98.79 mm (3.8697 ± 3.8894 in.)
Exhaust98.84 ± 99.34 mm (3.8913 ± 3.9110 in.)
Minimum overall length:
Intake98.19 mm (3.8657 in.)
Exhaust98.74 mm (3.8874 in.)
If the overall length is less than minimum, replace the valve.
(e) Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, resurface the tip with a grinder or
replace the valve.
NOTICE:
Do not grind off more than the minimum overall length.
7. INSPECT AND CLEAN VALVE SEATS
(a) Using a 45° carbide cutter, resurface the valve seats.
Remove only enough metal to clean the seats.
(b) Check the valve seating position.
Apply a thin coat of Prussian blue (or white lead) to the
valve face. Lightly press the valve against the seat. Do not
rotate the valve.
(c) Check the valve face and seat for the following:

If blue appears 360° around the face, the valve is
concentric. If not, replace the valve.

If blue appears 360° around the valve seat, the
guide and face are concentric. If not, resurface the
seat.

Check that the seat contact is in the middle of the
valve face with the following width:
If not, correct the valve seats as follows:
Intake1.0 ± 1.4 mm (0.039 ± 0.055 in.)
Exhaust1.2 ± 1.6 mm (0.047 ± 0.063 in.)
(1) If the seating is too high on the valve face, use 15°
and 45° cutters to correct the seat.

A02820
EM2011
EM2538
A02817
Plastigage
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±45
1399 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
9. INSPECT CAMSHAFTS FOR RUNOUT
(a) Place the camshaft on V±blocks.
(b) 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 maximum, replace the cam-
shaft.
10. INSPECT CAM LOBES
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake44.310 ± 44.360 mm (1.7445 ± 1.7465 in.)
Exhaust44.250 ± 44.350 mm (1.7421 ± 1.7461 in.)
Minimum cam lobe height:
Intake44.16 mm (1.7386 in.)
Exhaust44.10 mm (1.7362 in.)
If the cam lobe height is less than minimum, replace the cam-
shaft.
11. INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
Journal diameter:
28.949 ± 28.965 mm (1.1397 ± 1.1404 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
12. INSPECT CAMSHAFT BEARING
Check the bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cyl-
inder head as a set.
13. INSPECT CAMSHAFT JOURNAL OIL CLEARANCE
(a) Clean the bearing caps and camshaft journals.
(b) Place the camshafts on the cylinder head.
(c) Lay a strip of Plastigage across each of the camshaft jour-
nals.
(d) Install the bearing caps. (See page EM±52)
Torque: 20 N´m (200 kgf´cm, 14 ft´lbf)
NOTICE:
Do not turn the camshaft.
(e) Remove the bearing caps.

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.

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.