1998 Lexus LS400 overheating

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.

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.

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

IN CASE OF AN EMERGENCY
196
CAUTION
When making the connections, to avoid serious injury, do not
lean over the battery or accidentally let the jumper cables or
clamps touch anything except the correct battery terminals or
the ground.
5. Start your engine in the normal way. After starting, run it at about
2000 rpm for several minutes with the accelerator pedal lightly
depressed.
6. Carefully disconnect the cables in the exact reverse order: the
negative cable and then the positive cable.
7. Carefully dispose of the battery cover cloths which may now
contain sulfuric acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is not apparent (for example,
lights left on), you should have it checked.
IF YOUR VEHICLE OVERHEATS
If your engine coolant temperature gauge indicates overheating,
if you experience a loss of power, or if you hear a loud knocking
or pinging noise, the engine has probably overheated.
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your emergency
flashers. Put the transmission in ”P” and apply the parking brake.
A: If steam is coming from your engine:
Turn off the engine. Leave the hood closed until there is no sign of
steam or coolant. Your engine could have been seriously damaged
already. Call your Lexus dealer for assistance.
CAUTION
To help avoid personal injury, keep the hood closed until there
is no steam. Escaping steam or coolant is sign of very high
pressure.

INDEX (C E)
279
Consumer information
Uniform tire quality grading 244. . . . . . . . . . .
Controls, Instrument panel Pictorial index. . . . . .
Cooling system
Coolant level 233. . . . . . . . . . . . . . . . . . . . . . .
Engine overheating 196. . . . . . . . . . . . . . . . . .
Radiator and reservoir 233. . . . . . . . . . . . . . . .
Radiator cap 196. . . . . . . . . . . . . . . . . . . . . . .
Winter driving tips 182. . . . . . . . . . . . . . . . . . .
Corrosion prevention 270
Cruise control 168. . . . . . . . . . . . . . . . . . . . . . . .
Cruise information 42. . . . . . . . . . . . . . . . . . . . .
Cup holder 56. . . . . . . . . . . . . . . . . . . . . . . . . . . D
Defogger, Rear window 27. . . . . . . . . . . . . . . . .
Dimmer switch, Headlight 5, 24. . . . . . . . . . . .
Directional signals 5, 24. . . . . . . . . . . . . . . . . . .
Discharge warning light 39. . . . . . . . . . . . . . . . .
Does your vehicle need repairing? 217. . . . . . . .
Doityourself maintenance 221. . . . . . . . . . . .
Door locks 18. . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver’s seat 2, 70. . . . . . . . . . . . . . . . . . . . . . . .
Driving
Automatic transmission 160. . . . . . . . . . . . . . .
Driving tips 180. . . . . . . . . . . . . . . . . . . . . . . .
Driving position memory system 113. . . . . . . . . .
Driving tips
Driving tips in various conditions 181. . . . . . .
Driving with an automatic
transmission 160. . . . . . . . . . . . . . . . . . . . . .
Economical driving 189. . . . . . . . . . . . . . . . . .
Good braking practice 176. . . . . . . . . . . . . . . .
Good driving practice 166
Winter driving tips 182. . . . . . . . . . . . . . . . . . .
During breakin 181. . . . . . . . . . . . . . . . . . . . . .
E
Economical driving .
Saving money on both fuel and
repairs 189. . . . . . . . . .
Electrical system
Battery 253. 257. . . . . . . . . . . . . . . . . . . . . . . .
Fuse locations 249. . . . . . . . . . . . . . . . . . . . . .
Fuses 249, 258, 260. . . . . . . . . . . . . . . . . . . . .
Spark plugs 226. . . . . . . . . . . . . . . . . . . . . . . .
Electronic throttle control system 167. . . . . . . .
Emergency flasher switch 31. . . . . . . . . . . . . . .
Emergency, in case of
Blown fuse 259. . . . . . . . . . . . . . . . . . . . . . . .
Emergency flasher switch 31. . . . . . . . . . . . . .
Flat tire 197. . . . . . . . . . . . . . . . . . . . . . . . . . .
If you lose your keys 210
If your vehicle needs to be towed 205. . . . . . .
If your vehicle will not start 193. . . . . . . . . . .
Jump starting 194. . . . . . . . . . . . . . . . . . . . . . .
Overheating 196. . . . . . . . . . . . . . . . . . . . . . . .
Towing 205. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine
Antifreeze 233. . . . . . . . . . . . . . . . . . . . . . . . .
Before starting the engine 157. . . . . . . . . . . . .

INDEX (E G)
280
Checking the coolant level 233. . . . . . . . . . . .
Coolant 233. . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant temperature gauge 34. . . . . . . . . . . . .
Emission control device 155. . . . . . . . . . . . . .
Engine compartment 220 . . . . . . . . . . . . . . . . .
Exhaust gas caution 156. . . . . . . . . . . . . . . . . .
Hood release 62. . . . . . . . . . . . . . . . . . . . . . . .
Oil consumption 229. . . . . . . . . . . . . . . . . . . .
Oil level 230. . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheating 196. . . . . . . . . . . . . . . . . . . . . . . .
Spark plugs 226. . . . . . . . . . . . . . . . . . . . . . . .
Starting procedure 159. . . . . . . . . . . . . . . . . . .
Threeway catalytic converter 155. . . . . . . . .
Engine coolant, Winter driving tips 182. . . . . . .
Engine immobiliser system 10. . . . . . . . . . . . . .
Engine oil, Winter driving tips 182. . . . . . . . . . .
Engine coolant temperature gauge 34. . . . . . . . .
Exhaust gas caution 156. . . . . . . . . . . . . . . . . . . F
Facts about engine oil consumption 229. . . . . . .
Flasher, Headlight 5, 24. . . . . . . . . . . . . . . . . . .
Flat tire
After changing wheels 204. . . . . . . . . . . . . . . .
Changing tires 202. . . . . . . . . . . . . . . . . . . . . .
If you have a flat tire 197 . . . . . . . . . . . . . . . . .
Jack point 201. . . . . . . . . . . . . . . . . . . . . . . . .
Jacking precautions 197. . . . . . . . . . . . . . . . . .
Jacking up 201. . . . . . . . . . . . . . . . . . . . . . . . .
Loosening wheel nuts 201 . . . . . . . . . . . . . . . . .
Lowering vehicle 203. . . . . . . . . . . . . . . . . . . .
Reinstalling wheel ornament 204. . . . . . . . . . .
Removing wheel ornament 200. . . . . . . . . . . .
Wheel block 200. . . . . . . . . . . . . . . . . . . . . . .
Wheel nuts 201. . . . . . . . . . . . . . . . . . . . . . . . .
Floor mat 58. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid level
Brake 239. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine coolant 233. . . . . . . . . . . . . . . . . . . . . .
Power steering 240. . . . . . . . . . . . . . . . . . . . . .
Washer fluid 261. . . . . . . . . . . . . . . . . . . . . . .
Fog light 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign countries, Operation in 181. . . . . . . . . . Front seat
Lumbar support 73. . . . . . . . . . . . . . . . . . . . . .
Position 71. . . . . . . . . .
Seat cushion angle and height 72. . . . . . . . . . .
Seatback angle 72. . . . . . . . . . . . . . . . . . . . . . .
Fuel
Filler door opener 65. . . . . . . . . . . . . . . . . . . .
Fuel economy 189. . . . . . . . . . . . . . . . . . . . . .
Fuel information 227. . . . . . . . . . . . . . . . . . . .
Gauge 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MTBE 228. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation in foreign countries 181. . . . . . . . . .
Tank cap 65. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuse
Blade type fuses 258. . . . . . . . . . . . . . . . . . . .
Cartridge type fuses 260. . . . . . . . . . . . . . . . . .
Fuse locations 249. . . . . . . . . . . . . . . . . . . . . . . .
Fuse box 220. . . . . . . . . . . . . . . . . . . . . . . . . . . .
G
Garage door opener 54. . . . . . . . . . . . . . . . . . . .
Gas station information Inside back cover. . . . .
Gauge
Engine coolant temperature 34. . . . . . . . . . . . .
Fuel 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glovebox 54. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Good driving practice 166 . . . . . . . . . . . . . . . . . .