1999 Lexus LS400 engine overheat

DRIVING TIPS
337

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 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 tuned±up 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

SECTION 4
340
IN CASE OF AN EMERGENCY
If your engine stalls while driving341
. . . . . . . . . . . . . . . .
If your vehicle will not start 342
. . . . . . . . . . . . . . . . . . . . .
If your vehicle overheats 347
. . . . . . . . . . . . . . . . . . . . . . .
If you have a flat tire 349
. . . . . . . . . . . . . . . . . . . . . . . . . . .
If your vehicle needs to be towed 366
. . . . . . . . . . . . . . .
If you cannot shift automatic transmission
selector lever 375
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you lose your keys or lock yourself out 377
. . . . . . . . .

IN CASE OF AN EMERGENCY
342
IF YOUR VEHICLE WILL NOTSTART
(a) Simple checks
Before making these checks, make sure you have
followed the correct starting procedure instructions in
ºHow to start the engineº on page 280 and that you have
sufficient fuel. Since your vehicle is equipped with the
engine immobiliser system, also check whether the
other keys will start the engine. If they work, your key
may be broken. Have the key checked at your Lexus
dealer. If none of your keys work, the system is possibly
broken. Call your Lexus dealer. See ºKeysº on page 9.
If the engine is not turning over or is turning over too
slowly ±
1. Check that the battery terminals are tight and clean.
2. If the battery terminals are O.K., switch on the interior
light.
3. If the light is out, dim or goes out when the starter is
cranked, the battery is discharged. You may try jump
starting. See º(c) Jump startingº for further instruction.
If the light is O.K., but the engine still will not start, it
needs adjustment or repair. Call a Lexus dealer,
Roadside Assistance or Customer Service Assistance.
(See ºForewordº.)
NOTICE
Do not pull± or push±start the vehicle. It may damage the vehicle or cause a collision when theengine starts. Also the three±way catalyticconverter may overheat and become a fire hazard.
If the engine turns over at its normal speed but will
not start ±
1. The engine may be flooded because of repeated
cranking. See º(b) Starting a flooded engineº for further
instructions.
2. If the engine still will not start, it needs adjustment or
repair. Call a Lexus dealer, Roadside Assistance or
Customer Service Assistance. (See ºForewordº.)

IN CASE OF AN EMERGENCY
343
(b) Starting a flooded engine
If the engine will not start, your engine may be
flooded because of repeated cranking.
If this happens, turn the key to ºSTARTº with the
accelerator pedal held down. Continue this operation for
30 seconds and then stop cranking. Then try starting the
engine with your foot off the accelerator pedal.
If the engine does not start after 30 seconds of cranking,
release the key, wait a few minutes and try again.
If the engine still will not start, it needs adjustment or
repair. Call a Lexus dealer, Roadside Assistance or
Customer Service Assistance. (See ºForewordº.)
NOTICE
Do not crank for more than 30 seconds at a time. This may overheat the starter and wiring systems.

IN CASE OF AN EMERGENCY
347
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.

IN CASE OF AN EMERGENCY
348
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your
emergency flashers. Put the transmission in ºPº 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.

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