engine overheat JEEP WRANGLER 2004 TJ / 2.G Owners Manual

15. Coolant Temperature Gauge
Indicates engine coolant temperature. The red
zone to the far right indicates possible overheat-
ing. Seek authorized service immediately if the
gauge operates in the red zone. In U.S. vehicles,
temperature is indicated in degrees fahrenheit; in
Canadian vehicles in degrees centigrade.
16. Airbag Warning Light
This indicator lights and remains lit for 6 to
8 seconds when the ignition is first turned
on. If the light does not come on for 6 to 8
seconds, stays on or comes on while driving,
have the airbag system checked by an authorized
dealer.
17. Check Gauges Warning Light
This light monitors the engine coolant tem-
perature, engine oil pressure, and voltage
gauges. If it detects an extreme condition a
chime will sound and the light will come on. If the
light comes on, check the operation of these gauges for
a malfunction condition.18. Malfunction Indicator Light
This light is a part of an Onboard Diagnostic
System called OBD II that monitors engine,
and automatic transmission control systems.
The light will illuminate when the ignition is in the
ON position before engine start. If the bulb does not
come on when turning the key from OFF to ON, have
the condition checked promptly.
Certain conditions such as a loose or missing gas cap,
poor quality fuel, etc. may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several typical driving styles. In most
situations, the vehicle will drive normally and will not
require towing.
When the engine is running, the ªMalfunction Indicator
Lightº may flash to alert serious conditions that could
lead to immediate loss of power or severe catalytic
converter damage. The vehicle should be serviced as
soon as possible if this occurs.
118 UNDERSTANDING YOUR INSTRUMENT PANEL

NOTE:For improved safety, the A/C compressor is
activated when ªMixº or ªDefrostº modes are selected.
This is done to assist in drying the air and it will help in
keeping the windshield from fogging.
Operating Tips
Summer Operation
The engine cooling system in air conditioned vehicles
must be protected with a high-quality antifreeze coolant
to provide proper corrosion protection and to protect
against engine overheating. A 50% solution of ethylene
glycol antifreeze coolant in water is recommended.
Winter Operation
The air from the heater system will heat faster in cold
weather if you use lower blower speeds until the engine
warms up.
REAR WINDOW FEATURES Ð HARD TOP ONLY
Rear Window Defogger
To turn the rear window defogger on, press the
rocker switch. If you press the switch a second
time, you will turn the defogger off. A light on the rocker
switch will indicate the defogger is on.
The defogger will automatically turn off after about ten
minutes. For five more minutes of operation, depress the
top of the switch to turn the defogger on again. To
prevent excessive battery drain use the defogger only
when the engine is operating.
154 UNDERSTANDING YOUR INSTRUMENT PANEL

²Do not downshift into a low gear while traveling at too
high a speed for that gear. Engine, clutch, or transmis-
sion damage may result.
²Do not rest your foot on the clutch pedal. This causes
heat buildup and damages the clutch.
²When you slow down or go up a grade, downshift as
speed requires or the engine may overheat.
²Never hold the vehicle stopped on a hill by using the
clutch pedal. The clutch may be damaged.
²During cold weather, you may experience increased
effort in shifting until the transmission fluid warms
up. This is normal.
²Push in the clutch pedal completely when shifting.
Otherwise, transmission or clutch damage may result.
²When ªrockingº a stuck vehicle by shifting between a
forward gear and reverse, do not spin wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
²The manual transmission may be equipped with a
ªReverse Blockerº to prevent inadvertent shifts from
5th gear to Reverse. If you experience difficulty shift-
ing into ªReverseº, make sure that you are not inad-
vertently moving the shift lever toward 5th gear when
shifting into ªReverse.º
Recommended Manual Transmission Shifting
Speeds
The ªShift Indicator Lightº in the instrument cluster
reminds you when to shift to the next higher gear (4.0L
Only). The manufacturer recommends that you use the
SIL for normal driving. The desired shift speeds are listed
in the chart below.
Manual Transmission Shift Speeds in MPH (KM/H)
Engine Speeds 1 to 2 2 to 3 3 to 4 4 to 5
2.4L Accel. 15 (24) 25 (40) 40 (64) 45 (72)
Cruise 15 (24) 25 (40) 40 (64) 45 (72)
4.0L Accel. 14 (23) 23 (37) 36 (58) 44 (71)
Cruise 14 (23) 20 (32) 28 (45) 38 (61)
164 STARTING AND OPERATING

2 (Second)
For moderate grades and to assist braking on dry
pavement or in mud and snow. Begins at a stop in low
gear with automatic upshift to 2nd gear. Will not shift
to 3rd.
1 (First)
For hard pulling at low speeds in mud, sand, snow, or
on steep grades. Begins and stays in low gear with no
upshift. Provides engine compression braking at low
speeds.
WARNING!
Never use P (Park) position with an automatic trans-
mission as a substitute for the parking brake. Al-
ways apply parking brake fully when parked to
guard against vehicle movement and possible injury
or damage.
CAUTION!
²Before moving the shift lever out of P (Park), you
must turn the ignition from LOCK so the steering
wheel and shift lever are released. Otherwise,
damage to steering column or shifter could result.
²Never race the engine with the brakes on and the
vehicle in gear, and never hold the vehicle on an
incline without applying the brakes. These prac-
tices can overheat and damage the transmission.
²When ªrockingº a stuck vehicle by moving be-
tween D (Drive) and R (Reverse), do not spin the
wheels faster than 15 mph (24 km/h), or drivetrain
damage may result.
STARTING AND OPERATING 169
5

WARNING!
To use your brakes and decelerate more safely, follow these
tips:
²Do not ªrideº the brakes by resting your foot on the pedal.
This could overheat the brakes and result in unpredictable
braking action, longer stopping distances, or brake damage.
²When descending mountains or hills, repeated braking can
cause brake fade with loss of braking control. Avoid
repeated heavy braking by downshifting the transmission
whenever possible.
²Do not downshift on icy or slippery roads, because engine
braking may cause skidding and loss of control.
²Engines may idle at higher speeds during warm-up, which
could cause rear wheels to spin and result in loss of vehicle
control. Be especially careful while driving on slippery
roads, in close-quarter maneuvering, parking or stopping.
Remember, always engage 4-wheel drive when driving on
slippery roads.
²Do not drive too fast for road conditions, especially when
roads are wet or slushy. A wedge of water can build up
between the tire tread and the road. This hydroplaning
action can cause loss of traction, braking ability, and
control. Under such conditions, engage 4-wheel drive.
²After going through deep water or a car wash, brakes may
become wet, resulting in poor performance and unpredict-
able braking action. Dry the brakes by gentle, intermittent
pedal action while driving at very slow speeds.
WARNING!
The weight and position of cargo and passengers can
change the vehicle center of gravity and vehicle han-
dling. To avoid loss of control resulting in personal
injury, follow these guidelines:
²Always place cargo evenly on the cargo floor, and
locate heavier objects as low and as far forward as
possible.
²Place as much cargo as possible in front of the rear
axle. Too much weight or improperly placed weight
over or behind the rear axle can cause the rear of the
vehicle to sway.
²Do not pile luggage or cargo higher than the top of
the seatback. This could impair visibility or become
a dangerous projectile in a sudden stop or collision.
²The rear cargo space is intended for load carrying
purposes only, not for passengers, who should sit in
seats and use seat belts.
²On hardtop models, do not drive with the lift glass
up. On fabric top models, do not drive with the rear
window curtain up unless the side curtains are also
open. This will prevent dangerous exhaust fumes
from entering the vehicle.
178 STARTING AND OPERATING

WHAT TO DO IN EMERGENCIES
CONTENTS
mHazard Warning Flasher.................210
mIf Your Engine Overheats................210
mChanging A Flat Tire...................211
NTool Kit Location.....................211
NJack Location........................211NSpare Tire Location....................213
NTire Changing Procedures...............213mJump Starting.........................216
mTowing A Disabled Vehicle...............2196

HAZARD WARNING FLASHER
The flasher switch is on top of the steering column, just
behind the steering wheel. Depress the switch and both
cluster indicators and all front and rear directional sig-
nals will flash. Depress the switch again to turn Hazard
Warning Flashers off.Do not use this emergency warning system when the
vehicle is in motion. Use it when your vehicle is disabled
and is creating a safety hazard for other motorists.
If it is necessary to leave the vehicle to go for service, the
flasher system will continue to operate with the ignition
key removed and the vehicle locked.
NOTE:With extended use, the flasher may wear down
your battery.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate ac-
tion.
²On the highways Ð Slow down.
²In city traffic Ð While stopped, put transmission in N
(Neutral), but do not increase engine idle speed.
NOTE:There are steps that you can take to slow down
an impending overheat condition. If your air conditioner
is on, turn it off. The air conditioning system adds heat to
the engine cooling system and turning off the A/C
removes this heat. You can also turn the Temperature
210 WHAT TO DO IN EMERGENCIES

Inspect the drive belt for evidence of cuts, cracks, or
glazing and replace them if there is any sign of damage
which could result in belt failure. If adjustment is re-
quired, adjust the belts according to the specifications
and procedures shown in the Service Manual.
Special tools are required to properly measure tension
and to restore belt tension to factory specifications. Also,
check belt routing to make sure there is no interference
between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the mileage specified in the appropriate main-
tenance chart. The entire set should be replaced if there is
any malfunction due to a faulty spark plug.
Refer to the ªVehicle Emission Control Informationº label
in the engine compartment for spark plug information.
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter as an emission control device.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
232 MAINTAINING YOUR VEHICLE

WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing that can burn.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe
and abnormal catalyst overheating. If this occurs, stop
the vehicle, turn off the engine and allow it to cool.
Service, including a tune up to manufacturer's specifica-
tions, should be obtained immediately.
To minimize the possibility of catalytic converter dam-
age:
²Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
²Do not try to start the engine by pushing or towing the
vehicle.
²Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing.
²Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
²Do not allow vehicle to run out of fuel.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Engine Timing Belt Ð 2.4L Engine
Replace the engine timing belt at the intervals described
in the appropriate maintenance schedule.
Ignition Wiring System Ð 2.4L Engine
Replace the ignition cables at the intervals described in
the appropriate maintenance schedule.
MAINTAINING YOUR VEHICLE 233
7

Adding Coolant
When adding coolant, a minimum solution of recom-
mended 50% ethylene glycol antifreeze coolant in water
should be used. Use higher concentrations (not to exceed
70%) if temperatures below -37ÉF (-38ÉC) are anticipated.
Use only high purity water such as distilled or deionized
water when mixing the water/antifreeze solution. The
use of lower quality water will reduce the amount of
corrosion protection in the engine cooling system.
NOTE:Mixing coolant types will decrease the life of the
engine coolant and will require more frequent engine
coolant changes.
Please note that it is the owner's responsibility to main-
tain the proper level of protection against freezing ac-
cording to the temperatures occurring in the area where
the vehicle is operated.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
coolant, and to insure that coolant will return to the
radiator from the coolant reserve tank.The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
The warning words DO NOT OPEN HOT on the
cooling system pressure cap are a safety precaution.
Never add coolant when the engine is overheated.
Do not loosen or remove the cap to cool an over-
heated engine. Heat causes pressure to build up in
the cooling system. To prevent scalding or injury, do
not remove the pressure cap while the system is hot
or under pressure.
Coolant Level
The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. The
coolant level must be at the FULL mark or above the
ADD mark on the bottle.
The radiator normally remains completely full, so there is
not need to remove the radiator cap unless checking for
coolant freeze point or replacing coolant. Advise your
MAINTAINING YOUR VEHICLE 241
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