60
The gauge indicates the engine cool-
ant 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,
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 con-
ditioning 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 tocontrol the flow of coolant to keep
the temperature of the engine within the specified operatingrange.
Do not continue driving with an
overheated engine. See If yourvehicle overheatsº in Part 4.
The oil pressure gauge indicates en-
gine oil pressure when the ignition
switch is on. Check it while driving to
make sure that the needle is in the
proper range.
If the oil pressure should stay below the
normal range, pull off the road to a safe
place and stop the engine immediately.
Call a Toyota dealer or qualified repair
shop for assistance.
Oil pressure may not built up when the oil
level is too low. The oil pressure gauge is not designed to indicate oil level, and the
oil level must be checked using the leveldipstick.
Oil pressure gauge
Engine coolant temperature gauge
122
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of lubri-
cating 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 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 isleft 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 com-
bustion gases during the combustionprocess.
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 driving
and frequent acceleration and deceleration.
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 re-
peated short trips, and consumes a normal
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 be-
cause the oil is gradually becoming diluted
with the fuel or moisture, making it appear
that the oil level has not changed.
The diluting ingredients evaporate out
when the vehicle is then driven at high
speeds, as on an expressway, making it appear that oil is excessively consumed
after driving as high speeds.
IMPORTANCE OF ENGINE OIL LEVELCHECK
One of the most important points in proper vehicle maintenance is to keep the engine
oil at the optimum level so that oil function
will
not be impaired. Therefore, it is essen-
tial that the oil level be checked regularly.
Toyota recommends that the oil level bechecked every time you refuel the vehicle.
NOTICE
Failure to check the oil level regularly could lead to serious
engine trouble due to insufficient oil.
Facts about engine oil consumption
166lever in ºPº position and all brakes re- leased.
IN THE ENGINE COMPARTMENT Items listed below should be checked
from
time to time , e.g. each time when
refueling.
Washer fluid
Make sure there is sufficient fluid in the
tank. See Chapter 7-3 for additional infor-
mation.
Engine coolant level Make sure the coolant level is between
the FULLº and LOWº lines on the see-
through reservoir when the engine is cold.
See Chapter 7-2 for additional informa-tion.
Battery electrolyte level Make sure the electrolyte level of all bat-
tery cells is between upper and lower level
lines on the case. Add only distilled water
when replenishing. See Chapter 7-3 for
additional information. Brake fluid level
Make sure the brake fluid level is correct. See Chapter 7-2 for additional informa- tion.
Engine oil level
Check the l evel on the dipstick with the en-
gine turned off and the vehicle parked on a level spot. See Chapter 7-2 for addition-
al information. Power steering fluid level Check
the level through the reservoir. The
level should be in the HOTº or COLDº
range depending on the fluid t emperature.
See Chapter 7-2 for additional informa-tion.
Exhaust system
If you notice any change in the sound of
the exhaust or smell exhaust fumes, have the cause located and corrected immedi-
ately. (See engine exhaust cautions in
Part 2.) Be on the alert for changes in perfor-
mance, sounds, and visual tip-offs
that in-
dicate service is needed. Some important
clues are as follows: Engine missing, stumbling, or pinging
Appreciable loss of power
Strange engine noises
A leak under the vehicle (however, wa-
ter dripping from the air conditioning
after use is normal.)
Change in exhaust sound (This may
indicate a dangerous carbon monox-
ide leak. Drive with the windows open
and have the exhaust system checked
immediately.)
Flat-looking tire; excessive tire squeal
when cornering; uneven tire wear
Vehicle pulls to one side when drivingstraight on a level road
Strange noises related to suspensionmovement
Loss of brake effectiveness; spongy
feeling brake or clutch pedal; pedal al-
most touches floor; vehicle pulls to one
side when braking
Engine coolant temperature continual-
ly higher than normal
Does your vehicle need repairing?