1999 TOYOTA CAMRY CNG cooling

64
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 moves into the red zone,
your engine is too hot. If your vehicle
overheats, 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 con-
trol 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 “If your ve-
hicle overheats” in Part 4.
Tachometer
The tachometer indicates engine speed
in thousands of rpm
( revolutions per
minute). Use it while driving to select
correct shift points and to prevent en-
gine lugging and overrevving.
Driving with the engine running too fast
causes excessive engine wear and poor
fuel economy. Remember, in most cases
the slower the engine speed, the greater
the fuel economy.
NOTICE
Do not let the indicator needle get
into the red zone. This may cause
severe engine damage.
Engine coolant temperature
gauge

92
If following another vehicle on a dusty
road, or driving in windy and dusty
conditions, it is recommended that the
air intake selector be temporarily set to
RECIRCULATE, which will close off the
outside passage and prevent outside
air and dust from entering the vehicle
interior.Heating
For best results, set controls to:
Fan speed—Any setting except “OFF”
Temperature—To w a r d s WARM
(red zone)
Air intake—FRESH (outside air)
Air flow—FLOOR
Air conditioning—OFF
For quick heating, select recirculated
air for a few minutes. To keep the
windows from fogging, select fresh af-
ter the vehicle interior has been
warmed.
Press the “A/C” button on for dehumidi-
fied heating.
Choose floor/windshield air flow to heat
the vehicle interior while defrosting or
defogging the windshield.Air conditioning
For best results, set controls to:
Fan speed—Any setting except “OFF”
Temperature—To w a r d s COLD
(blue zone)
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—ON
For quick cooling, move the air intake
selector to recirculate for a few min-
utes.
Ventilation
For best results, set controls to:
Fan speed—Any setting except “OFF”
Temperature—To w a r d s COLD
(blue zone)
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—OFF

93
Defogging
The inside of the windshield
For best results, set controls to:
Fan speed—Any setting except “OFF”
Temperature—To w a r d s WARM
(red zone) to heat;
COLD (blue zone) to
cool
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
Turning the Air Flow Selector to wind-
shield position turns on the defroster to
clear the front view more quickly.
Press the “A/C” button for dehumidified
heating or cooling. This setting clears the
front view more quickly.
On humid days, do not blow cold air
on the windshield—the difference be-
tween the outside and inside tempera-
tures could make the fogging worse.Defrosting
The outside of the windshield
For best results, set controls to:
Fan speed—Any setting except “OFF”
Temperature—To w a r d s WARM
(red zone)
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
Turning the Air Flow Selector to wind-
shield position turns on the defroster to
clear the front view more quickly.
Press the “A/C” button for dehumidified
heating. This setting clears the front view
more quickly.
To heat the vehicle interior while de-
frosting the windshield, choose
floor/windshield air flow.
Side vents
If air flow control is not satisfactory, check
the side vents. The side vents may be
opened or closed as shown.

107
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 CNG (Compressed Natural
Gas).
Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three−
way catalytic converter.
Do not allow the engine to run at
idle speed for more than 20 min-
utes.
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/distributor ignition system
or fuel system could cause an ex-
tremely 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 autho-
rized Toyota CNG dealer knows
your vehicle and its three−way cata-
lytic converter system best.
To ensure that the three−way cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the separate “Owner’s
Manual Supplement”.
Engine exhaust cautions
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 run-
ning. 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.

108
Keep the trunk lid closed while
driving. An open or unsealed trunk
lid may cause exhaust gases to be
drawn into the vehicle.
To allow proper operation of your
vehicle’s ventilation system, keep
the inlet grilles in front of the wind-
shield clear of snow, leaves, or oth-
er obstructions.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the trunk lid closed. Have
the cause immediately located and
corrected.
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume 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 pis-
ton 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 tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by high−speed driv-
ing and frequent acceleration and decel-
eration.
A new engine consumes more oil, since
its pistons, piston rings and cylinder walls
have not become conditioned.
When judging the amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately.
As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal amount of oil, the dipstick may not
show any drop in the oil level at all, even
after 1000 km (600 miles) or more. This
is because the oil is gradually becoming
diluted with fuel or moisture, making it
appear that the oil level has not changed.
Facts about engine oil
consumption

131
If your engine coolant temperature
gauge indicates overheating, if you ex-
perience a loss of power, or if you hear
a loud knocking or pinging noise, the
engine has probably overheated. You
should follow this procedure...
1. Pull safely off the road, stop the ve-
hicle and turn on your emergency
flashers. Put the transmission in “P”
and apply the parking brake. Turn off
the air conditioning if it is being used.
2. If coolant or steam is boiling out of the
radiator or reservoir, stop the engine.
Wait until the steam subsides before
opening the hood. If there is no coolant
boiling over or steam, leave the engine
running and make sure the electric
cooling fan is operating. If it is not,
turn the ignition off.
CAUTION
To help avoid personal injury, keep
the hood closed until there is no
steam. Escaping steam or coolant is
a sign of very high pressure.
3. Look for obvious coolant leaks from the
radiator, hoses,and under the vehicle.
However, note that water draining from
the air conditioning is normal if it has
been used.
CAUTION
When the engine is running, keep
hands and clothing away from the
moving fan and engine drive belts.
4. If the coolant is leaking, stop the en-
gine immediately. Call your authorized
Toyota CNG dealer for assistance.
5. If there are no obvious leaks, check
the coolant reservoir. If it is dry, add
coolant to the reservoir while the en-
gine is running. Fill it about half full.
CAUTION
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.
6. After the engine coolant temperature
has cooled to normal, again check the
coolant level in the reservoir. If neces-
sary, bring it up to half full again. Seri-
ous coolant loss indicates a leak in the
system. You should have it checked as
soon as possible at your authorized
Toyota CNG dealer.
If your vehicle overheats

158
Engine compartment overview
1. Power steering fluid reservoir
2. Engine coolant reservoir
3. Engine oil filler cap
4. Engine oil level dipstick
5. Brake fluid reservoir
6. Fuse blocks
7. Battery
8. Electric cooling fans
9. Windshield washer fluid tank

160
If you perform maintenance by yourself,
be sure to follow the correct procedure
given in this part.
You should be aware that improper or in-
complete servicing may result in operating
problems.
Performing do−it−yourself maintenance
during the warranty period may affect your
warranty coverage. Read the separate
Toyota Warranty statement for details and
suggestions.
This part gives instructions only for those
items that are relatively easy for an owner
to perform. As explained in Part 6, there
are still a number of items that must be
done by a qualified technician with special
tools.
For information on tools and parts for do−
it−yourself maintenance, see “Parts and
tools”.
Utmost care should be taken when work-
ing on your vehicle to prevent accidental
injury. Here are a few precautions that
you should be especially careful to ob-
serve:CAUTION
Never work on the fuel system by
yourself. Any work on this system
must be performed by your autho-
rized Toyota CNG dealer. If an un-
qualified person works on it incor-
rectly causing fuel leaks etc., a fire
hazard or explosion may occur,
which is very dangerous.
When the engine is running, keep
hands, clothing, and tools away
from the moving fan and engine
drive belts. (Removing rings,
watches, and ties is advisable.)
Right after driving, the engine
compartment—the engine, radiator,
exhaust manifold and spark plug
boots, etc.—will be hot. So be care-
ful not to touch them. Oil, fluids
and spark plugs may also be hot.
If the engine is hot, do not remove
the radiator cap or loosen the drain
plugs to prevent burning yourself.
Do not smoke, cause sparks or al-
low open flames around fuel or the
battery. Their fumes are flammable.
Be extremely cautious when work-
ing on the battery. It contains poi-
sonous and corrosive sulfuric acid.
Do not get under your vehicle with
just the body jack supporting it. Al-
ways use automotive jack stands or
other solid supports.
Be sure that the ignition is off if
you work near the electric cooling
fans or radiator grille. With the
ignition on, the electric cooling fans
will automatically start to run if the
engine coolant temperature is high
and/or the air conditioning is on.
Use eye protection whenever you
work on or under your vehicle
where you may be exposed to flying
or falling material, fluid spray, etc.
Used engine oil contains potentially
harmful contaminants which may
cause skin disorders such as in-
flammation or skin cancer, so care
should be taken to avoid prolonged
and repeated contact with it. To re-
move used engine oil from your
skin, wash thoroughly with soap
and water.
Do−it−yourself service
precautions