cooling JEEP WRANGLER 2008 JK / 3.G Owners Manual

MAX A/C
For maximum cooling, select ei-
ther the Panel or Bi-Level position
using the mode control. Then,
press the “A/C” and the “Recir-
culate” buttons so that both lamps
are illuminated, and set the tem-
perature control to its coolest set-
ting.
NOTE:
•Recirculation Mode will not operate in floor, mix or
defrost modes.
•Refer to “Recirculation Control” in this section, for
proper or extended use of this position.
Operating Tips
Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it’s rainy or humid. In most cases
turning on the air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield. Adjust the temperature
control and blower speed to maintain comfort. Higher
blower speeds will reduce fogging. Interior fogging on
the windshield can be quickly removed by selecting the
defrost mode.
UNDERSTANDING YOUR INSTRUMENT PANEL 265
4

Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette
smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Fluids and
Genuine Parts in Section 7 for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift intoNEUTRAL (N) and depress the accelerator slightly for
fast idle operation to increase coolant flow and fan speed.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e., vacation) for two weeks or more, run the air
conditioning system at idle for about five minutes in the
fresh air and high blower setting. This will ensure
adequate system lubrication to minimize the possibility
of compressor damage when the system is started again.
266 UNDERSTANDING YOUR INSTRUMENT PANEL

CAUTION!
Muddy waters can reduce the cooling system effec-
tiveness by depositing debris onto the radiator.
Crossing Ditches, Streams, Shallow Rivers Or
Other Flowing Water
Flowing water can be extremely dangerous. Never at-
tempt to cross a fast running stream or river even in
shallow water. Fast moving water can easily push your
vehicle downstream sweeping it out of control. Even in
very shallow water, a high current can still wash the dirt
out from around your tires putting you and your vehicle
in jeopardy. There is still a high risk of personal injury
and vehicle damage with slower water currents in depths
greater than the vehicle’s running ground clearance. You
should never attempt to cross flowing water which is
deeper than the vehicle’s running ground clearance. Eventhe slowest current can push the heaviest vehicle down-
stream out of control if the water is deep enough to push
on the large surface area of the vehicle’s body. Before you
proceed determine the speed of the current, the water’s
depth, approach angle, bottom condition and if there are
any obstacles, then cross at an angle heading slightly
upstream using the low and slow technique.WARNING!
Never drive through fast moving deep water. It can
push your vehicle downstream, sweeping it out of
control. This could put you and your passengers at
risk of injury or drowning.
306 STARTING AND OPERATING

Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
CAUTION!
Front or rear wheel lifts should not be used. Internal
damage to the transmission or transfer case will occur
if a front or rear wheel lift is used when recreational
towing.
Towing – 2WD Models
Recreational towing is allowed ONLY if the rear drive-
shaft is removed. See your authorized dealer or refer to
the Service Manual. Towing with the rear wheels on the
ground while the driveshaft is connected can result in
severe transmission damage.
STARTING AND OPERATING 359
5

IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate ac-
tion.
•On the highways — Slow down.
•In city traffic — While stopped, shift transmission into
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 HOT
(H), 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 HOT (H), and you hear continuous
chimes, turn the engine off immediately, and call for
service.
WHAT TO DO IN EMERGENCIES 365
6

▫Driveline And Steering Component
Lubrication ..........................392
▫ Body Lubrication .....................392
▫ Windshield Wiper Blades ................392
▫ Windshield And Rear Window Washers .....393
▫ Exhaust System ......................393
▫ Cooling System .......................394
▫ Hoses And Vacuum/Vapor Harnesses .......399
▫ Brake System ........................399
▫ Automatic Transmission ................401
▫ Hydraulic Clutch Fluid — Manual
Transmission ........................403
▫ Manual Transmission ..................403
▫ Transfer Case ........................404 ▫
Front/Rear Axle Fluid ..................405
▫ Maintenance After Off-Road Driving ........405
▫ Appearance Care And Protection From
Corrosion ...........................406
 Fuses (Totally Integrated Power Module) ......413
 Vehicle Storage ........................419
 Replacement Bulbs — If Equipped ...........420
 Bulb Replacement ......................420
▫ Head Light ..........................420
▫ Front Park/Turn Signal .................421
▫ Front Side Marker .....................422
▫ Front Fog Light ......................422
▫ Rear Tail, Stop, Turn Signal, And Backup
Lights .............................422
376 MAINTAINING YOUR VEHICLE

into the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
Cooling System
WARNING!
You or others can be badly burned by hot antifreeze/
coolant or steam from your radiator. If you see or hear
steam coming from under the hood, don’t open the
hood until the radiator has had time to cool. Never
try to open a cooling system pressure cap when the
radiator or coolant bottle is hot.
Engine Coolant Checks
Check antifreeze/coolant protection every 12 months
(before the onset of freezing weather, where applicable).
If antifreeze/coolant is dirty or rusty in appearance, thesystem should be drained, flushed and refilled with fresh
antifreeze/coolant. Check the front of the A/C condenser
(if equipped) or radiator for any accumulation of bugs,
leaves, etc. If dirty, clean by gently spraying water from a
garden hose vertically down the face of the A/C con-
denser (if equipped) or the back of the radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of the connection at
the coolant recovery bottle and radiator. Inspect the
entire system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
antifreeze/coolant from the radiator drain cock. If the cap
is sealing properly, the antifreeze/coolant will begin to
drain from the coolant recovery bottle. DO NOT RE-
MOVE THE COOLANT PRESSURE CAP WHEN THE
COOLING SYSTEM IS HOT.
394 MAINTAINING YOUR VEHICLE

Cooling System — Drain, Flush, And Refill
The cooling system should be drained, flushed, and
refilled, at the intervals shown on the Maintenance
Schedule. Refer to Section 8 of this manual.
If the solution is dirty and contains a considerable
amount of sediment, clean and flush with reliable cooling
system cleaner. Follow with a thorough rinsing to remove
all deposits and chemicals. Properly dispose of old
antifreeze/coolant solution.
Discard old antifreeze/coolant solution according to rec-
ommended procedure.
Selection Of Engine Coolant
Use only the manufacturer’s recommended antifreeze/
coolant. Refer to Fluids, Lubricants, and Genuine Parts in
this section for correct antifreeze/coolant type.
CAUTION!
•Mixing of antifreeze/coolants other than the speci-
fied HOAT antifreeze/coolants, may result in en-
gine damage and may decrease corrosion protec-
tion. If a non-HOAT antifreeze/coolant is
introduced into the cooling system in an emer-
gency, it should be replaced with the specified
antifreeze/coolant as soon as possible.
•Do not use plain water alone or alcohol-base
antifreeze/coolant products. Do not use additional
rust inhibitors or antirust products, as they may
not be compatible with the antifreeze/coolant and
may plug the radiator.
•This vehicle has not been designed for use with
Propylene Glycol based antifreeze/coolants. Use
of Propylene Glycol base antifreeze/coolants is not
recommended.
MAINTAINING YOUR VEHICLE 395
7

Adding Engine Coolant
Your vehicle has been built with an improved antifreeze/
coolant that allows extended maintenance intervals. This
antifreeze/coolant can be used up to 5 Years or 100,000
mi (160 000 km) before replacement. To prevent reducing
this extended maintenance period, it is important that
you use the same antifreeze/coolant throughout the life
of your vehicle. Please review these recommendations for
using Hybrid Organic Additive Technology (HOAT)
antifreeze/coolant. When adding antifreeze/coolant:
•The manufacturer recommends using MOPAR
Antifreeze/Coolant 5 Year/100,000 Mile Formula
HOAT (Hybrid Organic Additive Technology).
•Mix a minimum solution of 50% HOAT engine coolant
and distilled water. Use higher concentrations (not to
exceed 70%) if temperatures below -34°F (-37°C) are
anticipated.
•Use only high purity water such as distilled or deion-
ized water when mixing the water/engine coolant
solution. The use of lower quality water will reduce
the amount of corrosion protection in the engine
cooling system.
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.
NOTE: Mixing antifreeze/coolant types will decrease
the life of the antifreeze/coolant and will require more
frequent antifreeze/coolant changes.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
antifreeze/coolant, and to ensure that antifreeze/coolant
will return to the radiator from the coolant reserve tank.
396 MAINTAINING YOUR VEHICLE

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 antifreeze/coolant when the engine is
overheated. Do not loosen or remove the cap to cool
an overheated 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.
Disposal of Used Engine Coolant
Used ethylene glycol based antifreeze/coolant is a regu-
lated substance requiring proper disposal. Check with
your local authorities to determine the disposal rules for
your community. To prevent ingestion by animals orchildren, do not store ethylene glycol based antifreeze/
coolant in open containers or allow it to remain in
puddles on the ground. If ingested by a child, contact a
physician immediately. Clean up any ground spills im-
mediately.
Engine Coolant Level
The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. With the
engine idling, and warm to normal operating tempera-
ture, the level of the antifreeze/coolant in the bottle
should be between the ranges indicated on the bottle.
The radiator normally remains completely full, so there is
no need to remove the radiator cap unless checking for
antifreeze/coolant freeze point or replacing antifreeze/
coolant. Advise your service attendant of this. As long as
the engine operating temperature is satisfactory, the
coolant bottle need only be checked once a month.
MAINTAINING YOUR VEHICLE 397
7