1998 Lexus LS400 Coolant system

For detailed information, refer to the description given in each section.
PICTORIAL INDEX
ix
Page
1
Engine coolant temperature gauge 34
. . . . . . . . . . . . . . . . .
2 Tachometer 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
3 Turn signal indicator light 24
. . . . . . . . . . . . . . . . . . . . . . . .
4 Headlight indicator light 22
. . . . . . . . . . . . . . . . . . . . . . . . .
5 Headlight high beam indicator light 24
. . . . . . . . . . . . . . . .
6 Automatic transmission indicator lights 160
. . . . . . . . . . . .
7 Fuel gauge 34
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
8 Low fuel level warning light 40
. . . . . . . . . . . . . . . . . . . . . .
9 Cruise control indicator light 168
. . . . . . . . . . . . . . . . . . . . .
10 Height control indicator light 172
. . . . . . . . . . . . . . . . . . . .
11 Power mode indicator light 167
. . . . . . . . . . . . . . . . . . . . . .
12 Snow mode indicator light 167
. . . . . . . . . . . . . . . . . . . . . . .
13 Antilock brake system warning light 39
. . . . . . . . . . . . . . . Page
14 Vehicle skid control system off
indicator light 173
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 Malfunction indicator lamp 39
. . . . . . . . . . . . . . . . . . . . . . .
16 Slip indicator light 173
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17 Multi information display 41
. . . . . . . . . . . . . . . . . . . . . . . .
18 Odometer and trip meter 36
. . . . . . . . . . . . . . . . . . . . . . . . .
19 Brake system warning light 37
. . . . . . . . . . . . . . . . . . . . . . .
20 SRS warning light 38
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21 Open door warning light 39
. . . . . . . . . . . . . . . . . . . . . . . . .
22 Driver’s seat belt reminder light 38
. . . . . . . . . . . . . . . . . . .
23 Discharge warning light 39
. . . . . . . . . . . . . . . . . . . . . . . . . .
24 Instrument panel light control 46
. . . . . . . . . . . . . . . . . . . . .
25 ODO/TRIP RESET button 36
. . . . . . . . . . . . . . . . . . . . . . . .

For detailed information, refer to the description given in each section.
PICTORIAL INDEX
xi
Page
1
Engine coolant temperature gauge 34
. . . . . . . . . . . . . . . . .
2 Tachometer 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
3 Turn signal indicator light 24
. . . . . . . . . . . . . . . . . . . . . . . .
4 Tail light indicator light 22
. . . . . . . . . . . . . . . . . . . . . . . . . .
5 Headlight high beam indicator light 24
. . . . . . . . . . . . . . . .
6 Automatic transmission indicator lights 160
. . . . . . . . . . . .
7 Fuel gauge 34
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
8 Low fuel level warning light 40
. . . . . . . . . . . . . . . . . . . . . .
9 Cruise control indicator light 168
. . . . . . . . . . . . . . . . . . . . .
10 Power mode indicator light 167
. . . . . . . . . . . . . . . . . . . . . .
11 Snow mode indicator light 167
. . . . . . . . . . . . . . . . . . . . . . .
12 Antilock brake system warning light 39
. . . . . . . . . . . . . . . Page
13 Vehicle skid control system
off indicator light 173
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14 Malfunction indicator lamp 39
. . . . . . . . . . . . . . . . . . . . . . .
15 Slip indicator light 173
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16 Multi information display 41
. . . . . . . . . . . . . . . . . . . . . . . .
17 Odometer and trip meter 36
. . . . . . . . . . . . . . . . . . . . . . . . .
18 Brake system warning light 37
. . . . . . . . . . . . . . . . . . . . . . .
19 SRS warning light 38
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20 Open door warning light 39
. . . . . . . . . . . . . . . . . . . . . . . . .
21 Driver’s seat belt reminder light 38
. . . . . . . . . . . . . . . . . . .
22 Discharge warning light 39
. . . . . . . . . . . . . . . . . . . . . . . . . .
23 Instrument panel light control 46
. . . . . . . . . . . . . . . . . . . . .
24 ODO/TRIP RESET button 46
. . . . . . . . . . . . . . . . . . . . . . . .

GAUGES, METERS AND SERVICE REMINDER INDICATORS
35 Idling for a long period with the air conditioning on in
stopandgo traffic.
Towing a trailer.
NOTICE
Do not remove the thermostat in the engine cooling system as
this may cause the engine to overheat. The thermostat is
designed to control the flow of coolant to keep the
temperature of the engine within the specified operating
range.
Do not continue driving with an overheated engine. See ”If
your vehicle overheats” on page 196.
TACHOMETER
13L0031
The tachometer indicates engine speed in thousands of rpm
(revolutions per minute). Use it while driving to prevent engine
overrevving.
Driving with the engine running too fast causes excessive engine
wear and poor fuel economy. Remember, in most cases the slower
the engine speed, the greater the fuel economy.
NOTICE
Do not let the indicator needle get into the red zone. This may
cause severe engine damage.

STARTING AND DRIVING
162
31L008-3
1
Power mode 2
Normal mode 3
Snow mode
2. Set the driving pattern selector switch to the ”Normal”
position.
Your transmission has a driving pattern selector switch which allows
you to select ”Power”, ”Normal” or ”Snow” mode to suit your
driving condition. For ordinary driving, Lexus recommends that
you use the ”Normal” position to improve fuel economy.
3. For more powerful acceleration and sporty driving, use the
”Power” position.
In the POWER position, the ”ECT PWR” light in the instrument
cluster is on and the transmission is shifted up at higher vehicle
speeds and shifted down more responsively than in the NORMAL
position.
For ”Snow” mode, see ”Electronic Throttle Control System” on
page 167.
31l0552
1
”D” (Drive) position 2
Brake pedal
4. With your foot holding down the brake pedal, shift the
selector lever to ”D”.
Always use the ”D” position to improve fuel economy and quiet
driving. Only in this position, shifting into the overdrive gear is
possible. However, while the engine coolant temperature is low, the
transmission will not shift into the overdrive gear even in the ”D”
position. (See ”(b) Using engine braking” and ”(f) Good driving
practice” for exceptions.)
CAUTION
Never put your foot on the accelerator pedal while shifting.

MAINTENANCE
216Parking brake
Check that the pedal has the proper travel and that, on a safe incline,
your vehicle is held securely with only the parking brake applied.
Automatic transmission ”Park” mechanism
On a safe incline, check that your vehicle is held securely with the
selector lever in ”P” position and all brakes released.
Engine compartment
Items listed below should be checked from time to time, e.g. each
time when refueling.
Washer fluid
Make sure there is sufficient fluid in the tank. See page 261 for
additional information.
Engine coolant level
Make sure the coolant level is between the Upper and Lower lines
on the seethrough reservoir when the engine is cold. See page 233
for additional information.
Battery
Your Lexus has a maintenance free battery. You do not have to add
distilled water. For longer life of the battery, however, see page 253
for additional information.
Brake fluid level
Make sure the brake fluid level is correct. See page 239 for
additional information.Engine oil level
Check the level on the dipstick with the engine turned off and the
vehicle parked on a level spot. See page 230 for additional
information.
Power steering fluid level
Check the level on the dipstick. The level should be in the ”HOT”
or ”COLD” range depending on the fluid temperature. See page 240
for additional information.
Exhaust system
Look for cracks, holes and loose supports. If you notice any change
in the sound of the exhaust or smell exhaust fumes, have the cause
located and corrected immediately. (See engine exhaust cautions in
Section 31.)

MAINTENANCE
217
DOES YOUR VEHICLE NEED
REPAIRING?
Be on the alert for changes in performance and sounds, and visual
tipoffs that indicate service is needed. Some important clues are:
Engine missing, stumbling, or pinging
Appreciable loss of power
Strange engine noises
A fluid leak under the vehicle (However, water dripping from the
air conditioning after use is normal.)
Change in exhaust sound (This may indicate a dangerous carbon
monoxide leak. Drive with the windows open and have the
exhaust system checked immediately.)
Flatlooking tires, excessive tire squeal when cornering, uneven
tire wear
Vehicle pulls to one side when driving straight on a level road
Strange noises related to suspension movement
Loss of brake effectiveness, spongy feeling brake pedal, pedal
almost touches floors, vehicle pulls to one side when braking
Engine coolant temperature continually higher than normal
If you notice any of these clues, take your vehicle to your Lexus
dealer as soon as possible. It probably needs adjustment or repair.
CAUTION
Do not continue driving with the vehicle unchecked. It could
result in serious vehicle damage and possibly personal injury.

ENGINE
226 COOLING SYSTEM
Capacity
Coolant type
10.8 L (11.4 qt., 10.4 lmp.qt.)
Ethylene glycol coolant (Do not use alcohol type.)
FUEL
Fuel type
Octane rating
Only UNLEADED
91 (Research octane number 96) or higher
IGNITION SYSTEM
Spark plug Make DENSO
NGK
Gap
SK20R11
IFR6A11
1.1 mm (0.043 in.)
ELECTRICAL SYSTEM
Battery Maintenance type battery
Specific gravity reading at 20C (68F):
Charging rates Quick charge
Slow charge
Nonmaintenance battery
Open voltage at 20C (68F):
Charging rates
1.260 Fully charged
1.160 Half charged
1.060 Discharged
15A max.
5A max.
12.7V Fully charged
12.3V Half charged
11.9V Discharged
[Voltage that is checked 20 minutes after the key is removed with
all the lights turned off]
5A max.

ENGINE
233
CHECKING THE ENGINE
COOLANT LEVEL
62L007-2
1
Reservoir cap 2
Upper line 3
Lower line
Park the vehicle at a level spot and look at the seethrough
coolant reservoir when the engine is cool. The coolant level is
satisfactory if it is between the upper and lower lines on the tank.
If the level is low, add ethyleneglycol type coolant.
The coolant level in the reservoir will vary with engine coolant
temperature. However, if the level is on or below the lower line, add
coolant to bring the level up to the upper line.
Use only ethyleneglycol type coolant. It will prevent freezing and
corrosion. Neither supplemental inhibitors nor additives are needed
nor recommended. (For information on ethyleneglycol coolant,
see also ”Engine coolant selection” described below.)If the coolant level drops within a short time after replenishing, there
may be a leak in the system. Visually check the radiator, hoses,
reservoir cap, drain cock and water pump.
If you can find no leak, have your Lexus dealer test the cap pressure
and check for leaks in the cooling system.
CAUTION
To prevent burning yourself, do not remove the reservoir cap
when the engine is hot.
Engine coolant selection
Your coolant must contain ethyleneglycol antifreeze. In addition
to preventing freezing and subsequent damage to the engine, this
will also prevent corrosion. Further supplemental inhibitors or
additives are neither needed nor recommended.
Read the antifreeze container for information on freeze protection.
Follow the manufacturer’s directions for how much to mix with
water. The total capacity of the cooling system is given on page 226.
We recommend 50% solution be used for your Lexus, or a sufficient
quantity to provide protection to about 35C (31F).
NOTICE
Do not use alcohol type antifreeze or plain water alone.