engine overheat LEXUS SC300 1999 Owners Manual

SWITCHES
47
CAUTION
Occupants must use caution when operating the seat heater
because they may experience minor burns even at low
temperatures. 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 from 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
51
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.

Idling for a long period with the air conditioning on in
stop±and±go 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 ºIf your vehicle overheatsº on page 280.
TACHOMETER

STARTING AND DRIVING
210
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
three±way 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 three±way catalytic converter.
 Do not allow the engine to run at idle speed for more
than 20 minutes.
 Avoid racing the engine.
 Do not push±start or pull±start 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 or fuel system could cause
an extremely high three±way catalytic converter
temperature.
 If the engine becomes difficult to start or stalls
frequently, take your vehicle in for a check±up as soon
as possible. Remember, your Lexus dealer knows your
vehicle and its three±way catalytic converter system
best.
 To ensure that the three±way catalytic converter and
the entire emission control system operate properly,
your vehicle must receive the periodic inspections
required by the Lexus Maintenance Schedule. For
scheduled maintenance information, refer to the
separate ºOwner's Manual Supplement/
Maintenance Scheduleº.

STARTING AND DRIVING
216
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 ºPº. If you need to restart the
engine while the vehicle is moving, put the selector lever in
ºNº. 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 ºBefore crankingº.
Normal starting procedure
The multiport fuel injection system/sequential multiport fuel
injection system in your engine automatically controls the
proper air±fuel 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 ºSTARTº. 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 ºIf your vehicle will not startº on page 275.
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
224
(c) Using the º3º, º2º and ºLº positions
The º3º, º2º and ºLº positions are used for strong engine\
braking as described previously.
With the selector lever in º3º, º2º or ºLº, you can sta\
rt the
vehicle in motion as with the lever in ºDº.
With the selector lever in º3º or º2º, the vehicle will start in
the first gear and automatically shift to the third or second
gear.
With the selector lever in ºLº, 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:
º3º 153 km/h (96 mph) . . . .
º2º 100 km/h (63 mph) . . . .
ºLº 65 km/h (41 mph) . . . .
 Do not continue hill climbing or hard towing for a long
time in the º3º, º2º or ºLº position. This may cause
severe automatic transmission damage from
overheating. To prevent such damage, º4º position
should be used in hill climbing or hard towing.
(d) Backing up

STARTING AND DRIVING
227
(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 º4º position. Be
sure to shift the selector lever to the ºDº position after
climbing the slope.
 When towing a trailer, in order to maintain ef ficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the º4º 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 un±stuck, causing injury or damage to nearby
people or objects.

STARTING AND DRIVING
236
(c) Using the º2º and ºLº positions
The º2º and ºLº positions are used for strong engine braking
as described previously.
With the selector lever in º2º or ºLº, you can start the vehicle\
in motion as with the lever in ºDº.
With the selector lever in º2º, the vehicle will start in the first
gear and automatically shift to the second gear.
With the selector lever in ºLº, 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:
º2º 107 km/h (67 mph) . . . .
ºLº 56 km/h (35 mph) . . . .
 Do not continue hill climbing or hard towing for a long
time in the º2º or ºLº position. This may cause severe
automatic transmission damage from overheating. To
prevent such damage, º3º position should be used in
hill climbing or hard towing.

STARTING AND DRIVING
239
(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 º3º position. Be
sure to shift the selector lever to the ºDº position after
climbing the slope.
 When towing a trailer, in order to maintain ef ficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the º3º 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 un±stuck, causing injury or damage to nearby
people or objects.

DRIVING TIPS
260

Do 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 234.

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 high±speed
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 high±speed
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 a proper freeze protection of engine
coolant.
Your coolant must contain ethylene±glycol type coolant for
a proper corrosion protection of aluminum components. Use
ºToyota Long Life Coolantº or equivalent. See ºChecking
the engine coolant levelº on page 347 for instructions.
NOTICE
Do not use alcohol type antifreeze or plain water alone.
When it is extremely cold, we recommend to use 60%
solution for your Lexus, to provide protection down to about
±50 C (±58F). Do not use more than 70% solution for better
coolant performance.
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 380 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 346 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

DRIVING TIPS
268

Because of the added load of the trailer, your vehicle's
engine may overheat on hot days (at temperatures over
30C [85 F]) 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 ºIf your vehicle overheatsº on page 280 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 ºPº. 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 ºPº and turn off the engine.
When restarting out after parking on a slope:
1. With the transmission in ºPº position, start the engine. Be
sure to keep the brake pedal depressed. 2. Shift into the º3º, º2º, ºLº or ºRº 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.