1999 LEXUS SC300 cooling

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

AIR CONDITIONING AND AUDIO
182AIR mode is set.
If you push the ºFRONT WINDSHIELDº button once again
while in the FRONT WINDSHIELD mode, the mode then
returns to the last mode used.
CAUTION
Do not use the FRONT WINDSHIELD mode during cooled
air operation in extremely humid weather. The difference
between the temperature of the outside air and that of the
windshield could cause the outer surface of the windshield to
fog up blocking your vision.
If quick heating or cooling is desired ±
Obtain maximum power by turning the ºTEMPº knob fully.
At this time, ºMAX. HOTº or ºMAX. COLDº will appear on
the display.
If manual fan speed control is desired ±
The fan speed can be set to your desired speed by pushing
either
side of the fan speed control
(FAN) button. The
higher the fan speed is, the more air is delivered. Pushing in
the
(OFF) button turns off the fan.
To remove exterior windshield frost, use the high speed
setting. Stopping the fan ±
Push in the
(OFF) button.
The fan stops in automatic mode or manual mode.
If manual switching of air intake is desired ±
(AIR INTAKE) button is used to switch the air
intake between the OUTSIDE AIR mode and
RECIRCULATED AIR mode.
With the button in the OUTSIDE AIR mode, the OUTSIDE
AIR mode indicator light will come on and the system will
take fresh outside air into the vehicle.
If quick circulation of cooled air is desired, press in the air
intake control button for RECIRCULATED AIR. The
RECIRCULATED AIR mode indicator light will come on.
For normal use, it is best to keep the air intake control button

AIR CONDITIONING AND AUDIO
183
set to OUTSIDE AIR mode. If recirculated air is used during
heating, the windows will fog up more easily.
If manual on±off of the air conditioning is desired ±
Push the
(A/C) button to turn the air conditioning on
and push it again to turn the air conditioning off.
The air conditioning does not work if the outside temperature
is lowered down to around 0C (32F).
If the system is used for ventilation, heating in dry weather or
removing frost or exterior fog on the windshield, turn the air
conditioning off once it is no longer required. This will
improve fuel economy. The air conditioning can be used for
year±round automatic temperature control including cooling
and dehumidifying operation. If the air conditioning compressor does not operate, the
indicator of the
(A/C) button will blink. If the indicator
of the (A/C) button blinks even when the (A/C)
button is pushed again, have the compressor checked by your
nearest Lexus dealer.
(b) Windshield defogging and defrosting
See º(a) Climate controlº for details on each button.
To remove interior fog on the windshield ±
Push the
(WINDSHIELD) button.
To remove frost or exterior fog on the windshield ±
1. Place the temperature control knob at the maximum
temperature.
2. Push the
(WINDSHIELD) button.
3. Push the right side of the fan speed control
(FAN)
button to set the fan speed at the maximum speed.

STARTING AND DRIVING
211
ENGINE EXHAUST CAUTION
CAUTION
Avoid inhaling the engine exhaust. It contains carbon
monoxide, which is a colorless and odorless gas. It can
cause unconsciousness or even death.
 Make sure the exhaust system has no holes or loose
connections. The system should be checked from time to
time. If you hit something, or notice a change in the sound
of the exhaust, have the system checked immediately.
 Do not run the engine in a garage or enclosed area except
for the time needed to drive the vehicle in or out. The
exhaust gases cannot escape, making this a particularly
dangerous situation.
 Do not remain for a long time in a parked vehicle with the
engine running. If it is unavoidable, however, do so only in
an unconfined area and adjust the heating or cooling
system to force outside air into the vehicle.
 Keep the trunk lid closed while driving. An open or
unsealed trunk lid may cause exhaust gases to be drawn
into the vehicle.

IN CASE OF AN EMERGENCY
282B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning.
Check the following.


Is the cooling fan operating?

Is the coolant in the acceptable range?

Is the engine drive belt O.K.?
CAUTION

When the engine is running, keep hands and clothing away
from the moving fan and engine drive belt.

Do not attempt to remove the radiator cap when the engine
and radiator are hot. Serious injury could result from
scalding hot fluid and steam blown out under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus
dealer.
If both conditions are O.K., after the engine coolant
temperature has cooled to normal, continue driving your
vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible
by your Lexus dealer.

ENGINE
331
Oil capacity
Drain and refillwith filter
without filter
Oil grade
Recommended oil viscosity (SAE):
4.7 L (5.0 qt., 4.2 lmp.qt.)
4.8 L (5.1 qt., 4.2 lmp.qt.)
API SJ, ºEnergy±Conservingº multigrade engine oil or
ILSAC multigrade engine oil
± COOLING SYSTEM
Capacity
Coolant type
11.6 L (12.3 qt., 10.2 lmp.qt.)
ºToyota Long Life Coolantº or equivalent
With ethylene±glycol type coolant for a proper corrosion
protection of aluminum components
Do not use alcohol type antifreeze or plain water alone.
± FUEL
Fuel type
Octane rating
Only UNLEADED
91 (Research octane number 96) or higher

ENGINE
335
Oil capacity
Drain and refillwith filter
without filter
Oil grade
Recommended oil viscosity (SAE):
5.2 L (5.5 qt., 4.5 lmp.qt.)
4.9 L (5.2 qt., 4.4 lmp.qt.)
API SJ, ºEnergy±Conservingº multigrade engine oil or
ILSAC multigrade engine oil
± COOLING SYSTEM
Capacity
Coolant type
8.4 L (8.9 qt., 7.4 lmp.qt.)
ºToyota Long Life Coolantº or equivalent
With ethylene±glycol type coolant for a proper corrosion
protection of aluminum components
Do not use alcohol type antifreeze or plain water alone.
± FUEL
Fuel type
Octane rating
Only UNLEADED
91 (Research octane number 96) or higher

ENGINE
339
Gasolines quality
In a very few cases, you may experience driveability
problems caused by the particular gasoline that you are using.
If you continue to have unacceptable driveability, try
changing gasoline brands. If that does not rectify your
problem, then consult your Lexus dealer.
NOTICE

Do not use gasohol other than stated above. It will
cause fuel system damage or vehicle performance
problems.

If drivability problems are encountered (poor hot
starting, vaporizing, engine knock, etc.), discontinue
its use.

Take care not to spill gasohol during refueling.
Gasohol may cause paint damage.
Fuel tank capacity
78 L (20.6 gal., 17.2 lmp.gal.)
FACTS ABOUT ENGINE OIL
CONSUMPTION
Functions of engine oil
Engine oil has the primary function of lubricating and cooling
the inside of the engine, and plays a major role in maintaining
the engine in proper working order.
Engine oil consumption
It is normal that an engine should consume some engine
oil during normal engine operation. The causes of oil
consumption in a normal engine are as follows.

Oil is used to lubricate pistons, piston rings and cylinders.
A thin film of oil is left on the cylinder wall when a piston
moves downwards in the cylinder. High negative pressure
generated when the vehicle is decelerating sucks some of
this oil into the combustion chamber. This oil as well as
some part of the oil film left on the cylinder wall is burned
by the high temperature combustion gases during the
combustion process.

Oil is also used to lubricate the stems of the intake valves.
Some of this oil is sucked into the combustion chamber
together with the intake air and is burned along with the
fuel. High temperature exhaust gases also burn the oil
used to lubricate the exhaust valve stems.