1997 TOYOTA 4RUNNER Owners Manual

140
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 itappear that oil is excessively consumed
after driving as high speeds.
IMPORTANCE OF ENGINE OIL LEVEL CHECK
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 be checked every time you refuel the vehicle.
NOTICE
Failure to check the oil level regularly could lead to serious
engine trouble due to insufficientoil.
For detailed information on the oil level
check, see Checking the engine oil levelº
in Chapter 7-2.
Facts about engine oil consumption

141
Your engine is fitted with twin ground electrode spark plugs.
NOTICE
Use only twin ground electrode spark plugs for your engine perfor-
mance.
TANDEM MASTER CYLINDER BRAKE SYSTEM
The tandem master cylinder brake sys-
tem is a hydraulic system with two sepa-
rate sub-systems. If either sub-system
should fa il, the other will still work. Howev-
er, the pedal will be harder to press, and
your stopping distance will be longer.
Also, the brake system warning light may come on.
CAUTION!
Do not drive your vehicle with only a single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses engine vacuum to
power-assist the brakes. If the engine
should quit while you are driving, you can
bring the vehicle to a stop with normal
pedal pressure. There is enough reserve
vacuum for one or two stops - but nomore!
CAUTION!
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your vacuum re- serve.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push
the pedal hard-much harder than
normal. And your braking dis- tance will be longer
ANTI-LOCK BRAKE SYSTEM (with ABSº warning light)
The anti- lock brake system is designed to
automatically help prevent lock- up of the
wheels during sudden braking or braking on
slippery road surfaces. This assists in pro-
viding directional stability and steering per -
formance of the vehicle under these cir -
cumstances.
The anti- lock brake system becomes op-
erative after the vehicle has accelerated to
a speed in excess of approximately 10 km/h
(6 mph). It stops operating when the vehicle
decelerates to a speed below approximate-
ly 5 km/h (3 mph).
You may hear a sound in the engine
compartment for a few seconds when the
engine is started or just after the vehicle is started. This means that the anti-lock
brake system is in the self check mode,
and does not indicate a malfunction.
Twin ground electrode spark plugs (5VZ-FE engine)
Brake system

142
Effective way to press the ABSº brake
pedal: When the anti-lock brake system
function is in action, you may feel thebrake pedal pulsating and hear a noise.
In this situation, to let the anti-lock brake
system work for you, just hold the brake
pedal down more firmly. Do not pumpthe brake. This will result in reduced
braking performance.
The brake pedal pulsation caused by the
anti-lock brake system may indicate haz- ardous road surface conditions. Althoughthe anti-lock brake system assists in pro-
viding vehicle control, it is still important to
drive with all due care, because the anti-
lock brake system cannot overcome the
laws of physics that act on your vehicle: Braking capab ility is dependent on tire
friction with the road surface.
Even though the anti-lock brake sys-
tem is operating, a driver cannot main- tain full control on certain slippery road
surfaces, when cornering at highspeeds, or in violent maneuvers.
Avoid high speeds on wet roads. The
anti-lock brake system cannot elimi-
nate the risk of hydroplaning and lossof tire friction. Always maintain a safe distance from the
vehicle in
front of you. Compared with ve-
hicles not fitted with an anti-lock brake
system, your vehicle may require a longer
stopping distance in the following cases: Driving on rough, gravel or snow-cov-
ered roads.
Driving with tire chains installed.
Driving on roads where the road sur-
face is pitted or has other differencesin surface height.
CAUTION!
Do not use tires other than the
manufacturer 's designated tires, and
do not mix tires or wheels of different
sizes. You may prevent the antilockbrake system from operating at fulleffictiveness.
Vehicles with rear differential lock sys-
temÐThe anti-lock brake system does
not operate when the rear differential islocked. It is normal operation for the
ABSº warning light to be on at this time.Type A
Type B

143
ABSº warning light
This light comes on when the ignition key is turned to the ONº position. After about
3 seconds, the light will go off.
When the light is on with the rear dif
feren-
tial locked, it indicates the anti-lock brake
system will not operate.
If either of the following conditions occurs, this indicates a malfunction somewhere inthe parts monitored by the warning light
system. Contact your Toyota dealer as
soon as possible to service the vehicle. The light does not come on as de-
scribed above, or remains on.
The light comes on while driving with
the rear differential unlocked.
The light does not come on with the
rear differential locked.
The light comes on while driving. Even if the anti-lock brake system
should
fail, the brake system will still operate con-
ventionally. However, when the `ABS''
warning light is on (and the brake system
warning light is off), the anti-lock brake
system is not assisting brake perfor-mance so that the wheels can lock-up
during sudden braking or braking on slip-
pery road surfaces. Have your vehicle
checked by your Toyota dealer as soon as
possible
The brake pads wear limit indicators
on your disc brakes give a warning
noise w hen the brake pads are worn to
where replacement is required.
If you hear a squealing or scraping noise
while driving, have the brake pads
checked and replaced by your Toyota
dealer as soon as possible. Expensive ro-
tor damage can result if the pads are not
replaced when necessary.
Brake pad wear limit indicator

144
When stowing luggage or cargo in the ve-
hicle, observe the following:
Put luggage or cargo in the trunk when
at all possible. Be sure all items are se- cured in place.
Be careful to keep the vehicle bal-
anced. Locating the weight as far for-
ward as possible helps maintain bal- ance.
For better fuel economy, do not carryunneeded weight.
CAUTION!
To prevent luggage or packages
from sliding forward during brak-
ing, do not stack anything behind
the front seats higher than the seatbacks. Keep luggage or pack-
ages low, as close to the floor as possible.
Never allow anyone to ride in the
luggage compartment. It is not de-
signed for passengers. They
should ride in their seats with their
seat belts properly fastened.
Otherwise, they are much more
likely suffer serious bodily injury,
in the event of sudden braking or a collision.
Do not place anything on the filler
panel or luggage cover. Such items may be thrown about and
possibly injure people in the ve-
hicle during sudden braking or an
accident. (secure all items in a safe
place.)
Do not drive with objects left on
top of the instrument panel. They
may interfere with the driver's field
of view. Or they may move during
sharp vehicle acceleration or turn-ing, and impair the driver's control
of the vehicle. In an accident they
may injure the vehicle occupants.
NOTICE
Do not load the vehicle beyond the vehicle capacity weight specified in
Part 8.
The vehicle identification number
(VIN) is the legal identifier for your ve- hicle. This number is on the left top of
the instrument panel, and can be seen
through the windshield from outside.
This is the primary identification number
for your T oyota. It is used in registering the
ownership of your vehicle.
Luggage storage precautions
Your Toyota's identificationÐ
ÐVehicle identification number

145
The vehicle identification number (VIN) is
also on the Certification Label.3RZ-FE engine
5VZ-FE engineThe engine number is stamped on the
engine block as shown.
ÐEngine number

146
Your new vehicle carries theft preven-
tion labels which are approximately 56 mm (2.20 in.) by 16 mm (0.63 in.). The purpose of these labels is to reduce
the incidence of vehicle thefts by facilitat- ing the tracing and recovery of parts from
stolen vehicles. The label is designed so
that
once it is applied to a surface, any at-
tempt to remove it will result in destroying
the integrity of the label. Transferring
these la bels intact from one part to anoth-
er, will be impossible.
NOTICE
You should not attempt to remove the theft prevention labels as it may
violate certain state or federal laws.
CAUTION!
Do not modify the suspension/chas-
sis with lift kits, spacers, springs,
etc. It can cause dangerous handling
characteristics resulting in loss ofcontrol. Determine what kind of tires your ve-
hicle is originally equipped with.
1. Summer tires.
Summer tires are high-speed capability
tires best suited to highway driving underdry conditions. Since
summer tires do not have the same
traction performance as snow tires, sum-
mer tires are inadequate for driving on
snow-covered or icy roads. For driving on
snow-covered or icy roads, we recom-
mend using snow tires. If installing snow tires, be sure to replace all four tires.
2. All season tires
All season tires are designed to provide
better traction in snow and to be adequate
for driving in most winter conditions, as
well as for use all year round.
All season tires, however, do not have ad-
equate traction performance compared
with snow tires in heavy or loose snow.
Also, all season tires fall short in accelera-
tion and handling performance compared with summer tires in highway driving.
Suspension and chassis Types of tires
Theft prevention labels (except for Canada)

147
CAUTION!
Do not mix summer and all sea-
son tires on your vehicle as this
can cause dangerous handling
characteristics, resulting in loss
of control.
Do not use tires other than the
manufacturer 's designated tires,
and do not mix tires or wheels of
the sizes different from the originals.