1999 Lexus LS400 cooling

GAUGES, METERS AND SERVICE REMINDER INDICATORS
59
ENGINE COOLANT
TEMPERATURE GAUGE
13L002±2

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.
 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 thetemperature of the engine within the specifiedoperating range.
Do not continue driving with an overheatedengine. See ºIf your vehicle overheatsº onpage 347.

AIR CONDITIONING AND AUDIO
223
21L006-3
The outlets from which air is delivered can be selected
manually by pushing the button. The function of each
mode is as follows:
1Panel ± Air flows mainly from the instrument panel
vents.
2 Bi±level ± Air flows from both the floor vents and
the instrument panel vents.
3 Floor ± Air flows mainly from the floor vents.
4Floor/Windshield ± Air flows mainly from the floor
vents and windshield vents. If quick heating or cooling is desired ±
Push the ºTEMPº or ºPASSENGER TEMPº button on
either
side and hold it until ºMAX. HOTº or ºMAX. COLDº
appears on the display.
If manual fan speed control is desired ±

AIR CONDITIONING AND AUDIO
226
21L044
When you push either side of the ºTEMPº button several
times, the sensitivity changes from º+3º down to º±3º. If
you do not operate any button for a few seconds, the
previous display returns. If manual on±off of the air conditioning is desired ±
Push
the ºA/Cº 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 0 C (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 ºA/Cº button will blink. If the indicator of
the ºA/Cº button blinks even when the ºA/Cº button is
pushed again, have the compressor checked by your
nearest Lexus dealer.

STARTING AND DRIVING
274
To ensure that the three±way catalytic
converter and the entire emission controlsystem operate properly, your vehicle mustreceive the periodic inspections required bythe Lexus Maintenance Schedule. Forscheduled maintenance information, refer tothe separate ºOwner's Manual Supplement/
Maintenance Scheduleº.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.

IN CASE OF AN EMERGENCY
349
B: 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.IF YOU HAVE A FLAT TIRE
1. Reduce your speed gradually, keeping a straight line.
Move cautiously off the road to a safe place ± well away
from the traffic. Avoid stopping on the center divider of
a highway. Park on a level spot with firm ground.
2. Stop the engine and turn on your emergency flashers.
3. Firmly set the p arking brake and put the transmission
in ºPº.
4. Have everyone get out of the vehicle on the side away

INTRODUCTION
391
CAUTION

When the engine is running, keep hands, clothing,
and tools away from the moving fan and engine drive
belt. (Removing rings, watches, and ties is
advisable.)

Right after driving, the engine compartment ± the
engine, radiator, exhaust manifold and power
steering fluid reservoir, etc. ± will be hot. So be
careful not to touch them. Oil and other fluids may
also be hot.

Do not smoke, cause sparks or allow open flames
around fuel or the battery. Their fumes are
flammable.

Be extremely cautious when working on the battery.
It contains poisonous and corrosive sulfuric acid.

Do not get under your vehicle with just the body jack
supporting it. Always use automotive jack stands or
other solid supports.

Be sure the ignition is off if you work near the electric
cooling fan or radiator grille. With the ignition on, the
electric cooling fan may automatically start to run if
the air conditioning is on and/or if the coolant
temperature is high.

Use eye protection whenever you work on or under
your vehicle where you may be exposed to flying or
falling material, fluid spray, etc.

ENGINE
398± COOLING SYSTEM
Capacity
Coolant type
10.8 L (11.4 qt., 10.4 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.
± FUELFuel type
Octane rating
Only UNLEADED
91 (Research octane number 96) or higher
± IGNITION SYSTEMSpark plug ± Make DENSO NGK
± Gap
SK20R11
IFR6A11
1.1 mm (0.043 in.)

ENGINE
402
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 vehicleperformance problems.
If drivability problems are encountered (poorhot starting, vaporizing, engine knock, etc.),discontinue its use.
Take care not to spill gasohol during refueling.Gasohol may cause paint damage.
Fuel tank capacity
85 L (22.5 gal., 18.7 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.