engine coolant JEEP WRANGLER 2008 JK / 3.G Owners Manual

15. Tachometer
This light indicates the engine speed in revolutions per
minute (RPM).
CAUTION!
Do not operate the engine with the tachometer
pointer in the red area. Engine damage will occur.
16. Engine Coolant Temperature Warning Light This light warns of an overheated engine condi-
tion. If the engine is critically hot, a warning chime
will sound 10 times. After the chime turns off, the
engine will still be critically hot until the light goes out.
17. Sentry Key/Security Alarm Indicator Light — If
Equipped
Refer to “Sentry Key Immobilizer System” or “Vehicle
Security Alarm” in Section 2 of this manual. 18. Coolant Temperature Gauge
Indicates engine coolant temperature. The red
zone to the far right indicates possible overheat-
ing. Seek your authorized dealer immediately if
the gauge operates in the red zone. On U.S. vehicles, the
temperature is indicated in degrees fahrenheit; and on
Canadian vehicles in degrees centigrade.
19. Cruise Indicator Light This light shows when the electronic speed
control system is turned on.
20. 4WD Indicator Light — If Equipped This light alerts the driver that the vehicle is in
the four-wheel drive mode, and the front and
rear driveshafts are mechanically locked to-
gether forcing the front and rear wheels to
rotate at the same speed.
UNDERSTANDING YOUR INSTRUMENT PANEL 209
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

ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the cord
to a standard 110-115 Volt AC electrical outlet with a
grounded, three wire extension cord. The engine block
heater cord is found under the hood bundled in front of
the battery tray.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110-115 Volt AC electrical cord could
cause electrocution.
Use the heater when temperatures below 0°F (-18°C) are
expected to last for several days.
MANUAL TRANSMISSION
WARNING!
You or others could be injured if you leave the
vehicle unattended without having the parking
brake fully applied. The parking brake should al-
ways be applied when the driver is not in the vehicle,
especially on an incline.
CAUTION!
Never drive with your foot resting on the clutch
pedal, or attempt to hold the vehicle on a hill with the
clutch pedal partially engaged, as this will cause
abnormal wear on the clutch.
STARTING AND OPERATING 275
5

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

When additional antifreeze/coolant is needed to main-
tain the proper level, it should be added to the coolant
bottle. Do not overfill.
Points To Remember
NOTE:When the vehicle is stopped after a few miles of
operation, you may observe vapor coming from the front
of the engine compartment. This is normally a result of
moisture from rain, snow, or high humidity accumulat-
ing on the radiator and being vaporized when the
thermostat opens, allowing hot antifreeze/coolant to
enter the radiator.
If an examination of your engine compartment shows no
evidence of radiator or hose leaks, the vehicle may be
safely driven. The vapor will soon dissipate.
•Do not overfill the coolant bottle.
•Check antifreeze/coolant freeze point in the radiator
and in the coolant recovery bottle. If antifreeze/ coolant needs to be added, contents of coolant recov-
ery bottle must also be protected against freezing.
•If frequent antifreeze/coolant additions are required,
or if the level in the recovery bottle does not drop
when the engine cools, the cooling system should be
pressure-tested for leaks.
•Maintain antifreeze/coolant concentration at 50%
HOAT antifreeze/coolant (minimum) and distilled
water for proper corrosion protection of your engine
which contains aluminum components.
•Make sure that the radiator and coolant recovery
bottle hoses are not kinked or obstructed.
•Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean, also.
•Do not change the thermostat for summer or winter
operation. If replacement is ever necessary, install
398 MAINTAINING YOUR VEHICLE

FLUID CAPACITIES
U.S.Metric
Fuel (Approximate) — 2–Door Models 18.5 Gallons70 Liters
Fuel (Approximate) — 4–Door Models 22.5 Gallons85 Liters
Engine Oil with Filter
3.8 Liter Engine (SAE 5W-20, API Certified Engine Oil) 6 Quarts5.7 Liters
Cooling System *
3.8 Liter Engine (MOPAR Antifreeze/Engine Coolant 5 Year/
100,000 Mile Formula) 13 Quarts
12 Liters
* Includes heater and coolant recovery bottle filled to MAX level.
424 MAINTAINING YOUR VEHICLE

FLUIDS, LUBRICANTS AND GENUINE PARTS
Engine
ComponentFluid, Lubricant, or Genuine Part
Engine Coolant MOPARAntifreeze/Coolant 5 Year/100,000 Mile Formula HOAT (Hybrid
Organic Additive Technology)
Engine Oil Use API Certified SAE 5W-20 Engine Oil, meeting the requirements of
DaimlerChrysler Material Standard MS-6395. Refer to your engine oil filler cap
for correct SAE grade.
Spark Plugs (3.8L Engine) RE14PLP5 (Gap 0.050 in [1.27 mm])
Oil Filter (3.8L Engine) MOPAROil Filter (P/N 04105409AC)
Fuel Selection 87 Octane
MAINTAINING YOUR VEHICLE 425
7