2005 Lexus GX470 engine overheat

GAUGES, METERS AND SERVICE REMINDER INDICATORS
58
ENGINE COOLANT
TEMPERATURE GAUGE
Normal range
The gauge indicates the engine coolant temperature when
the ignition switch is on. The engine operating
temperature w ill 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.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
59
NOTICE
Do not remove the thermostat in the engine coolingsystem as this may cause the engine to overheat. Thethermostat is designed to control the flow of coolantto keep the temperature of the engine within thespecified operating range.
Do not continue driving with an overheated engine.See ªIf your vehicle overheatsº on page 496.

STARTING AND DRIVING
394
NOTICE
A large amount of unburned gases flowing into thethree±way catalytic converter may cause it to overheatand create a fire hazard. To prevent this and otherdamage, observe the following precautions:
Use only unleaded gasoline.
Do not drive with an extremely low fuel level; runningout of fuel could cause the engine to misfire, creatingan excessive load on the three±way catalyticconverter.
Do not allow the engine to run at idle speed for morethan 20 minutes.
Avoid racing the engine.
Do not push±start or pull±start your vehicle.
Do not turn off the ignition while the vehicle ismoving.
Keep your engine in good running order.Malfunctions in the engine electrical system, electricignition system or fuel system could cause anextremely high three±way catalytic convertertemperature.

STARTING AND DRIVING
407
(c) Using the ª3º, ª2º and ªLº positions
The ª3º, ª2º and ªLº positions are used for strong engine\
braking
as described previously.
With the selector lever in ª3º, ª2º or ªLº, you can start the vehicle
in motion as with the lever in ªDº.
With the selector lever in ª3º or ª2º, the vehicle will star\
t in first
gear and automatically shift to second gear.
With the selector lever in ªLº, the transmission is engaged in
first gear.
NOTICE
Be careful not to over±rev the engine. Watch the tachometer to keep engine rpm from going into thered zone. The approximate maximum allowablespeed for each position is given below for yourreference:
Transmission Transfer ªLº ªHº
ª3º 60 km/h (37 mph) 154 km/h (96 mph) ª2º 41 km/h (25 mph) 105 km/h (65 mph)ªLº 24 km/h (15 mph) 61 km/h (38 mph)
Do not continue hill climbing or hard towing for a long time in the ª3º, ª2º or ªLº position. This may causesevere automatic transmission damage from
overheating. To prevent such damage, ª4º positionshould be used in hill climbing or hard towing.

STARTING AND DRIVING
410
When towing a trailer, in order to maintain efficient engine
braking and electrical charging performance, do not use
overdrive.
CAUTION
Always keep your foot on the brake pedal while stopped
with the engine running. This prevents the vehicle from
creeping.
NOTICE
Always use the brake pedal or parking brake to hold the
vehicle on an upgrade. Do not attempt to hold the vehicle using the accelerator pedal, as this can causethe transmission to overheat.

DRIVING TIPS
462
CAUTION
Before driving off, make sure the parking brake is
fully released and that the parking brake reminder
light is off.
 Do not leave your vehicle unattended while the
engine is running.
 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 406.
 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 skid or spin.
 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.

DRIVING TIPS
481

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 ªIf your vehicle overheatsº on page 496.
 Always place wheel blocks under both the vehicle and trailer
wheels when parking. Apply the parking brake firmly. Put
the transmission in ªPº. 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 ªPº and turn off the engine. When restarting out after parking on a slope:
1. With the transmission in ªPº position, start the engine. Be
sure to keep the brake pedal depressed.
2. Shift into the ª3º, ª2º, ªLº or ªRº 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 vehicle±trailer 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
482
HOW TO SAVE FUEL AND MAKEYOUR VEHICLE LAST LONGER
Improving fuel economy is easy Ð 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 warm±up idling. Once the engine is
running smoothly, begin driving Ð but gently. Remember,
however, that on cold winter days this may take a little
longer.
 Always keep the automatic transmission selector lever
in the ªDº position when engine braking is not required.
Driving with the overdrive off will reduce the fuel economy.
(For details, see ªAutomatic transmissionº on page 403.)
 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 over±revving. Use a gear position suitable
for the road on which you are traveling.
 Avoid continuous speeding up and slowing down.
Stop±and±go driving wastes fuel.
 Avoid unnecessary stopping and braking. Maintain a
steady pace. Try to time the traffic si gnals 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
premature wear, overheating and poor fuel economy.
 Maintain a m oderate 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.