2004 JEEP GRAND CHEROKEE engine overheat

reaches the appropriate temperature. Refer to the ªNoteº
under ªTorque Converter Clutchº later in this section.
If the transmission temperature gets too hot, the trans-
mission may downshift out of Overdrive or engage
overdrive at higher vehicle speeds (4.7L engines only)
until the transmission cools down. After cooldown, Over-
drive will resume normal operation.
2ÐSecond
For driving slowly in heavy city traffic or on mountain
roads where more precise speed control is desirable. Use
it also when climbing long grades, and for engine brak-
ing when descending moderately steep grades. To pre-
vent excessive engine speed, do not exceed 45 mph (72
km/h) in this range.
1ÐFirst
For driving up very steep hills and for engine braking at
low speeds (25 mph (40 km/h) or less) when going
downhill. To prevent excessive engine speed do not
exceed 25 mph (40 km/h) in this range.
CAUTION!
Never 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 practices
can cause overheating and damage to the transmis-
sion.
184 STARTING AND OPERATING

Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the gear
selector rhythmically between ªFirstº and R (Reverse),
while applying slight pressure to the accelerator.
The least amount of accelerator pedal pressure to main-
tain the rocking motion without spinning the wheels or
racing the engine is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the transmission
selector in N (Neutral) for at least one minute after every
five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.CAUTION!
When ªrockingº a stuck vehicle by moving between
ªFirstº and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Selec-TracTOperating Instructions/Precautions
The Selec-Tracttransfer case provides five mode posi-
tions Ð two (rear) wheel drive high mode, part-time four
wheel drive high range, full-time four wheel drive high
range, neutral, and four wheel drive low range.
This transfer case is equipped with an inter-axle differ-
ential which allows driving the vehicle in the 4 FULL
TIME position at all times on any given road surface
including dry hard surfaced roads. The 4 FULL TIME
186 STARTING AND OPERATING

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 dis-
tances, or brake damage.
²When descending mountains or hills, repeated brak-
ing can cause brake fade with loss of braking control.
Avoid repeated heavy braking by downshifting the
transmission or locking out overdrive whenever pos-
sible.
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 maneuver-
ing, parking or stopping. Remember, always engage
4-wheel drive when driving on slippery roads (Selec-
Trac only). The Quadra-Trac II transfer case engages
four-wheel drive automatically when required.
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 (Selec-Trac only).
²After going through deep water or a car wash, brakes
may become wet, resulting in decreased performance
and unpredictable braking action. Dry the brakes by
gentle, intermittent pedal action while driving at very
slow speeds.
ON-ROAD DRIVING TIPS
Utility vehicles have higher ground clearance and a
narrower track to make them capable of performing in a
wide variety of off-road applications. Specific design
characteristics give them a higher center of gravity than
ordinary cars.
STARTING AND OPERATING 199
5

Always load a trailer with 60% of the cargo weight in the
front of the trailer. This places approximately 10% to 15%
of the GTW on the tow hitch of your vehicle. This portion
of the GTW becomes the tongue weight.
Trailer sway control and equalizing hitch are required for
tongue weights above 350 lbs (159 kg)., i.e., trailer
weights heavier than 3,500 lbs (1 587 kg).
Cooling System TipsÐTrailer Towing
To reduce potential for engine and transmission over-
heating in high ambient conditions, take the following
actions:
²City Traffic
When stopped, put transmission in N (Neutral) and
increase engine idle speed.
²Highway Driving
Reduce speed.
²Air Conditioning
Turn off temporarily.
To reduce the potential for transmission overheating,
turn the ªOverdriveº off when pulling any trailer or shift
the transmission to Drive position 2 on more severe
grades. Move the shift lever to the next lower position to
eliminate excessive transmission shifting. This action will
also reduce the possibility of transmission overheating
and provide better engine braking.
STARTING AND OPERATING 229
5

WHAT TO DO IN EMERGENCIES
CONTENTS
mHazard Warning Flashers.................236
mIf Your Engine Overheats.................237
mChanging A Flat Tire....................238
NJack And Lug Wrench Locations...........238
NSpare Tire Location....................239NTire Changing Procedure................242
mJump Starting Procedure..................246
mEmergency Tow Hooks Ð If Equipped........248
mTowing A Disabled Vehicle................248
6

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
Control to maximum heat, the Mode Control to floor, and
the Fan Control to High. This allows the heater core to act
as a supplement to the radiator and aids in removing heat
from the engine cooling system.
CAUTION!
Driving with a hot cooling system could damage
your vehicle. If the temperature gauge reads ªHº,
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the ªHº, and you hear continuous chimes, turn the
engine off immediately, and call for service.
WHAT TO DO IN EMERGENCIES 237
6

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.
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.
262 MAINTAINING YOUR VEHICLE

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
Check the coolant level at least once a month or more
often in hot weather. Check the level when the engine is
at normal operating temperature. Check the coolant level
only in the coolant recovery bottle. The coolant level
must be between the FULL and the ADD mark on the
bottle.
272 MAINTAINING YOUR VEHICLE