engine overheat lexus LS400 1998 Audio System / LEXUS 1998 LS400 OWNER'S MANUAL (OM50498U)

SWITCHES
32
SEAT HEATER SWITCHES
12L0132
The seat heater has two switches one marked ”L” (for the left
seat) and the other marked ”R” (for the right seat). Push these
switches to turn the respective seat heater on, and push the
switches again to turn them off.
The ignition key must be in the ”ON” position.
CAUTION
Occupants must use caution when operating the seat heater
because it may make them feel too hot or cause burns at low
temperatures (erythema, varicella). Use extra caution for;
Baby, small child, elderly person, sick person or
handicapped person
Persons who have delicate skin
Persons who are exhausted
Persons who have taken alcohol or drugs which induce
sleep (sleeping drug, cold remedy, etc.)
To prevent the seat overheating, do not use the seat heater with
a blanket, cushion, or other insulating objects which cover the
seat.
NOTICE
Do not put unevenly weighted objects on the seat and do not
stick sharp objects (needles, nails, etc.) into the seat.
When cleaning the seats, do not use organic substances
(paint thinner, benzine, alcohol, gasoline, etc.). They may
damage the heater and seat surface.
To prevent the battery from being discharging, turn the
switches on when the engine is running.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
34
FUEL GAUGE
13L0011
Low fuel level warning light
The gauge is displayed when the ignition switch is on and
indicates the approximate quantity of fuel remaining in the tank.
It is a good idea to keep the tank over 1/4 full.
If the fuel level approaches ”E” or the low fuel level warning light
comes on, fill the fuel tank as soon as possible.
On inclines or curves, due to the movement of fuel in the tank, the
fuel gauge needle may fluctuate or the low fuel level warning light
may come on earlier than usual.
If the fuel tank is completely empty, the malfunction indicator lamp
comes on. Fill the fuel tank immediately.
The indicator lamp goes off after driving several times. If the
indicator lamp does not go off, contact your Lexus dealer as soon as
possible.
See the inner back cover for fuel capacity and recommended fuelselection.
ENGINE COOLANT
TEMPERATURE GAUGE
13L0022
Normal range
The gauge indicates the engine coolant temperature when the
ignition switch is on. The engine operating temperature will
vary with changes in weather and engine load.
If the needle points to the red zone or higher, stop your vehicle and
allow the engine to cool.
Your vehicle may overheat during severe operating conditions, such
as:
Driving up a long hill on a hot day.
Reducing speed or stopping after high speed driving.

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
155
THREEWAY CATALYTIC
CONVERTER
31L0022
Threeway catalytic converters are emission control devices
installed in the exhaust system.
It looks somewhat like a muffler, but its purpose is to reduce
pollutants in the exhaust gas.
CAUTION
Keep people and combustible materials away from the
exhaust pipe while the engine is running. The exhaust gas
is very hot.
Do not drive, idle or park your vehicle over anything that
might burn easily such as grass, leaves, paper or rags.
NOTICE
A large amount of unburned gases flowing into the threeway
catalytic converter may cause it to overheat and create a fire
hazard. To prevent this and other damage, observe the following
precautions:
Use only unleaded gasoline.
Do not drive with an extremely low fuel level; running out of
fuel could cause the engine to misfire, creating an excessive
load on the threeway catalytic converter.
Do not allow the engine to run at idle speed for more than 20
minutes.
Avoid racing the engine.
Do not pushstart or pullstart your vehicle.
Do not turn off the ignition while the vehicle is moving.
Keep your engine in good running order. Malfunctions in the
engine electrical system, electronic ignition
system/distributor ignition system or fuel system could cause
an extremely high threeway catalytic converter
temperature.
If the engine becomes difficult to start or stalls frequently,
take your vehicle in for a checkup as soon as possible.
Remember, your Lexus dealer knows your vehicle and its
threeway catalytic converter system best.

STARTING AND DRIVING
159
HOW TO START THE ENGINE
Before cranking
1. Apply the parking brake firmly.
2. Turn off unnecessary lights and accessories.
3. Put the selector lever in ”P”. If you need to restart the engine
while the vehicle is moving, put the selector lever in ”N”. A starter
safety device will prevent the starter from operating if the selector
lever is in any drive position.
4. Depress the brake pedal and hold it to the floor until you are ready
to drive off.
Starting the engine
Before starting the engine, be sure to follow the instructions in
”Before cranking”.
Normal starting procedure
The multiport fuel injection system/sequential multiport fuel
injection system in your engine automatically controls the proper
airfuel mixture for starting. You can start a cold or hot engine as
follows:
1. With your foot off the accelerator pedal, crank the engine by
turning the key to ”START”. Release it when the engine starts.
2. After the engine runs for about 10 seconds, you are ready to drive.If the weather is below freezing, let the engine warm up for a few
minutes before driving. Do not leave the vehicle while the engine
is warming up.
If the engine stalls ...
Simply restart it , using the correct procedure given in normal
starting.
If the engine will not start
See ”If your vehicle will not start” on page 193.
NOTICE
Do not crank for more than 30 seconds at a time. This may
overheat the starter and wiring systems.
Do not race a cold engine.
If the engine becomes difficult to start or stalls frequently,
have the engine checked immediately.

STARTING AND DRIVING
164
3
Shift into the ”2” position. The transmission will downshift to
the second gear when the vehicle speed is or becomes lower
than 104 km/h (65 mph) and more powerful engine braking
than that of ”3” position will be obtained.
4
Shift into the ”L” position. The transmission will downshift to
the first gear when the vehicle speed is or becomes lower than
18 km/h (11 mph) and maximum engine braking will be
applied.
CAUTION
Be careful when downshifting on a slippery surface. The
abrupt change in engine speed could cause the vehicle to spin
or skid.
(c) Using the ”3”, ”2” and ”L” positions
The ”3”, ”2” and ”L” positions are used for strong engine braking as
described previously.
With the selector lever in ”3”, ”2” or ”L”, you can start the vehicle
in motion as with the lever in ”D”.
With the selector lever in ”3” or ”2”, the vehicle will start in the first
gear and automatically shift to the third or second gear.
With the selector lever in ”L”, the transmission is engaged in the first
gear.
NOTICE
Be careful not to overrev the engine. Watch the tachometer
to keep engine rpm from going into the red zone. The
approximate maximum allowable speed for each position is
given below for your reference:
”3” 160 km/h (99 mph). . . .
”2” 104 km/h (65 mph). . . .
”L” 68 km/h (42 mph). . . .
Do not continue hill climbing or hard towing for a long time
in the ”3”, ”2” or ”L” position. This may cause severe
automatic transmission damage from overheating. To
prevent such damage, ”4” position should be used in hill
climbing or hard towing.

STARTING AND DRIVING
166
(f) Good driving practice
If the transmission repeatedly upshifts and downshifts between
the fourth and overdrive gears when climbing a gentle slope, shift
the selector lever to the ”4” position. Be sure to shift the selector
lever to the ”D” position after climbing the slope.
When towing a trailer, in order to maintain efficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the ”4” position.
CAUTION
Always keep your foot on the brake pedal while stopped with
the engine running. This prevents the vehicle from creeping.
NOTICE
Do not hold the vehicle on an upgrade with the accelerator
pedal. This can cause the transmission to overheat. Always use
the brake pedal or parking brake.
(g) Rocking your vehicle if stuck
CAUTION
If your vehicle becomes stuck in snow, mud, sand, etc., then
you may attempt to rock the vehicle free by moving it forward
and backward. Do not attempt this procedure if people or
objects are anywhere near the vehicle. During the rocking
operation the vehicle may suddenly move forward or back as
it becomes unstuck, causing injury or damage to nearby
people or objects.
NOTICE
If you rock your vehicle, observe the following precautions to
prevent damage to the transmission and other parts.
Do not depress the accelerator pedal while shifting the
selector lever or before the transmission is completely shifted
to forward or reverse gear.
Do not race the engine and avoid spinning the wheels.
If your vehicle remains stuck after rocking the vehicle several
times, consider other ways such as towing.

DRIVING TIPS
182Do not rest your foot on the brake pedal while driving. It
can cause dangerous overheating, needless wear, and poor
fuel economy.
To drive down a long or steep hill, reduce your speed and
downshift. Remember, if you ride the brakes excessively,
they may overheat and not work properly. See page 163.
Be careful when accelerating, upshifting, downshifting or
braking on a slippery surface. The abrupt change in engine
speed, such as sudden acceleration or engine braking, could
cause the vehicle to spin or skid.
Do not drive in excess of the speed limit. Even if the legal
speed limit permits it, do not drive over 140 km/h (85 mph)
unless your vehicle has highspeed capability tires.
Driving over 140 km/h (85 mph) may result in tire failure,
loss of control and possible injury. Be sure to consult a tire
dealer to determine whether the tires on your vehicle are
highspeed capability tires or not before driving at such
speeds.
Do not continue normal driving when the brakes are wet.
If they are wet, your vehicle will require a longer stopping
distance, and it may pull to one side when the brakes are
applied. Also, the parking brake will not hold the vehicle
securely.
WINTER DRIVING TIPS
Make sure you have ethyleneglycol antifreeze in the radiator.
NOTICE
Do not use alcohol type antifreeze.
Check the condition of the battery and cables.
Cold temperatures reduce the capacity of any battery, so it must be
in top shape to provide enough power for winter starting. Page 253
tells you how to visually inspect the battery. Your Lexus dealer and
most service stations will be pleased to check the battery charge
level.
Make sure the engine oil viscosity is suitable for the cold weather.
See page 232 for recommended viscosity. Leaving a heavy summer
oil in your vehicle during winter months may cause harder starting.
If you are not sure about which oil to use, call your Lexus dealer
they will be pleased to help.
Check the electronic ignition system for loose connections or
obvious damage.
Keep the door locks from freezing.
Squirt lock deicer or glycerine into the locks to keep them from
freezing.

DRIVING TIPS
188Because of the added load of the trailer, your vehicle’s engine
may overheat on hot days (at temperatures over 30C [85F])
when going up a long or steep grade with a trailer. If the engine
coolant temperature gauge indicates overheating, immediately
turn off the air conditioning (if in use), pull your vehicle off the
road and stop in a safe spot. See ”If your vehicle overheats” on
page 196 of this manual.
Always place wheel blocks under both the vehicle and trailer
wheels when parking. Apply the parking brake firmly. Put the
transmission in ”P”. Avoid parking on a slope with a trailer, but
if it cannot be avoided, do so only after performing the following:
1. Apply the brakes and keep them applied.
2. Have someone place wheel blocks under both the vehicle and
trailer wheels.
3. When the wheel blocks are in place, release your brakes slowly
until the blocks absorb the load.
4. Apply the parking brake firmly.
5. Shift into ”P” and turn off the engine.When restarting out after parking on a slope:
1. With the transmission in ”P” position, start the engine. Be sure
to keep the brake pedal depressed.
2. Shift into the ”3”, ”2”, ”L” or ”R” position.
3. Release the parking brake and brake pedal and slowly pull or back
away from the wheel blocks. Stop and apply your brakes.
4. Have someone retrieve the blocks.
CAUTION
Do not exceed 72 km/h (45 mph) or the posted towing speed
limit, whichever is lower. Because instability (swaying) of
a towing vehicletrailer combination usually increases as
the speed increases, exceeding 72 km/h (45 mph) may cause
loss of control.
Slow down and downshift before descending steep or long
downhill grades. Do not make sudden downshifts.
Avoid holding the brake pedal down too long or too
frequently. This could cause the brakes to overheat and
result in reduced braking efficiency.

DRIVING TIPS
189
HOW TO SAVE FUEL AND MAKE
YOUR VEHICLE LAST LONGER
Getting more kilometer/mileage from a liter/gallon of fuel is easy
just take it easy. It will help make your vehicle last longer, too. Here
are some specific tips on how to save money on both fuel and repairs:
Keep your tires inflated at the correct pressure. Check the
pressure every two weeks, or at least once a month.
Underinflation causes tire wear and wastes fuel.
Do not carry unneeded weight in your vehicle. Excess weight
puts a heavier load on the engine, causing greater fuel
consumption.
Avoid lengthy warmup idling. Once the engine is running
smoothly, begin driving but gently. Remember, however, that
on cold winter days this may take a little longer.
Accelerate slowly and smoothly. Avoid jackrabbit starts.
Avoid long engine idling. If you have a long wait and you are
not in traffic, it is better to turn off the engine and start again later.
Avoid engine overrevving. Use a gear position suitable for the
road on which you are traveling.
Avoid continuous speeding up and slowing down.
Stopandgo driving wastes fuel.Avoid unnecessary stopping and braking. Maintain a steady
pace. Try to time the traffic signals so you only need to stop as
little as possible or take advantage of through streets to avoid
traffic lights. Keep a proper distance from other vehicles to avoid
sudden braking. This will also reduce wear on your brakes.
Avoid heavy traffic or traffic jams whenever possible.
Do not rest your foot on the brake pedal. This causes needless
wear, overheating and poor fuel economy.
Maintain a moderate speed on highways. The faster you drive,
the greater the fuel consumption. By reducing your speed, you
will cut down on fuel consumption.
Keep the front wheels in proper alignment. Avoid hitting the
curb and slow down on rough roads. Improper alignment not only
causes faster tire wear but also puts an extra load on the engine,
which, in turn, wastes fuel.
Keep the bottom of your vehicle free from mud, etc. This not
only lessens weight but also helps prevent corrosion.
Keep your vehicle tunedup and in top shape. A dirty air
cleaner, improper valve clearance, dirty plugs, dirty oil and
grease, brakes not adjusted, etc. all lower engine performance and
contribute to poor fuel economy. For longer life of all parts and
lower operating costs, keep all maintenance work on schedule,
and if you often drive under severe conditions, see that your
vehicle receives more frequent maintenance. (For scheduled
maintenance information, please refer to the separate ”Owner’s
Manual Supplement/Maintenance Schedule”.)
CAUTION