JEEP WRANGLER 2012 JK / 3.G Owners Manual

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.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
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:
•Do not shut off the engine or interrupt the ignition,
when the transmission is in gear and the vehicle is in
motion.
•Do not try to start the engine by pushing or towing the
vehicle.
•Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idle or malfunctioning operating conditions.
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Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
you see or hear steam coming from under the hood,
do not 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 the engine coolant (antifreeze) protection every
12 months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh engine coolant (anti-
freeze). Check the front of the A/C condenser (ifequipped) 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
engine coolant (antifreeze) from the radiator drain cock.
If the cap is sealing properly, the engine coolant (anti-
freeze) will begin to drain from the coolant recovery
bottle. DO NOT REMOVE THE COOLANT PRESSURE
CAP WHEN THE COOLING SYSTEM IS HOT.
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Cooling System – Drain, Flush, And Refill
If the engine coolant (antifreeze) 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 the old engine coolant (antifreeze).
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Selection Of Engine Coolant
Use only the manufacturer’s recommended engine cool-
ant (antifreeze). Refer to “Fluids, Lubricants, and Genu-
ine Parts” in “Maintaining Your Vehicle” for further
information.
CAUTION!
•Mixing of engine coolant (antifreeze) other than
the specified HOAT engine coolant (antifreeze)
may result in engine damage and may decrease
corrosion protection. If a non-HOAT engine cool-
ant (antifreeze) is introduced into the cooling
system in an emergency, it should be replaced with
the specified engine coolant (antifreeze) as soon as
possible.
•Do not use water alone or alcohol-based engine
coolant (antifreeze) products. Do not use addi-
tional rust inhibitors or antirust products, as they
may not be compatible with the antifreeze/engine
coolant (antifreeze) and may plug the radiator.
•This vehicle has not been designed for use with
Propylene Glycol based engine coolant (anti-
freeze). Use of Propylene Glycol base engine cool-
ant (antifreeze) is not recommended.
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Adding Engine Coolant
Your vehicle has been built with an improved engine
coolant (antifreeze) that allows extended maintenance
intervals. This engine coolant (antifreeze) can be used up
to five years or 104,000 miles (169 000 km) before
replacement. To prevent reducing this extended mainte-
nance period, it is important that you use the same
engine coolant (antifreeze) throughout the life of your
vehicle.
Please review these recommendations for using Hybrid
Organic Additive Technology (HOAT) engine coolant
(antifreeze). When adding engine coolant (antifreeze):
•The manufacturer recommends using MOPAR
Antifreeze/Coolant 5 Year/100,000 Mile Formula
HOAT (Hybrid Organic Additive Technology) or
equivalent.
•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
(antifreeze) 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 engine coolant (antifreeze) types will
decrease the life of the engine coolant (antifreeze) and
will require more frequent coolant changes.
532 MAINTAINING YOUR VEHICLE

Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that engine coolant
(antifreeze) 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 engine coolant (antifreeze) when the en-
gine 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 engine coolant (antifreeze) is
a regulated substance requiring proper disposal. Check
with your local authorities to determine the disposal
rules for your community. To prevent ingestion by ani-
mals or children, do not store ethylene glycol based
engine coolant (antifreeze) in open containers or allow it
to remain in puddles on the ground. If ingested by a child
or pet, seek emergency assistance immediately. Clean up
any ground spills immediately.
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 engine coolant (antifreeze) in the
bottle should be between the ranges indicated on the
bottle.
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The radiator normally remains completely full, so there is
no need to remove the radiator cap unless checking for
engine coolant (antifreeze) freeze point or replacing en-
gine coolant (antifreeze). 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.
When additional engine coolant (antifreeze) is needed to
maintain 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/
kilometers of operation, you may observe vapor coming
from the front of the engine compartment. This is nor-
mally a result of moisture from rain, snow, or high
humidity accumulating on the radiator and being vapor-
ized when the thermostat opens, allowing hot engine
coolant (antifreeze) 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 the engine coolant (antifreeze) freeze point in
the radiator and in the coolant recovery bottle. If
engine coolant (antifreeze) needs to be added, the
contents of the coolant recovery bottle must also be
protected against freezing.
•If frequent engine coolant (antifreeze) 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 the engine coolant (antifreeze) concentration
at 50% HOAT engine coolant (antifreeze) (minimum)
and distilled water for proper corrosion protection of
your engine which contains aluminum components.
534 MAINTAINING YOUR VEHICLE

•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.
•Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory cooling performance, poor gas
mileage, and increased emissions.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
WARNING!
Riding the brakes can lead to brake failure and
possibly a collision. Driving with your foot resting or
riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You would not have your full
braking capacity in an emergency.
Power Disc Brakes
Disc brakes do not require adjustment; however, several
hard stops during the break-in period are recommended
to seat the linings and wear off any foreign material.
Brake Master Cylinder
The fluid level in the master cylinders should be checked
whenever the vehicle is serviced. If necessary, add fluid
to bring level to the full level mark on the side of the
reservoir of the brake master cylinder. With disc brakes,
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MAINTAINING YOUR VEHICLE 535

fluid level can be expected to fall as the brake pads wear.
If the brake fluid level is abnormally low, check system
for leaks.
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information.
WARNING!
•Use only manufacturer’s recommended brake
fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further
information. Using the wrong type of brake fluid
can severely damage your brake system and/or
impair its performance. The proper type of brake
fluid for your vehicle is also identified on the
original factory installed hydraulic master cylin-
der reservoir.(Continued)
WARNING! (Continued)
•To avoid contamination from foreign matter or
moisture, use only new brake fluid or fluid that
has been in a tightly closed container. Keep the
master cylinder reservoir cap secured at all times.
Brake fluid in a open container absorbs moisture
from the air resulting in a lower boiling point.
This may cause it to boil unexpectedly during hard
or prolonged braking, resulting in sudden brake
failure. This could result in a collision.
•Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing
the brake fluid to catch fire. Brake fluid can also
damage painted and vinyl surfaces, care should be
taken to avoid its contact with these surfaces.(Continued)
536 MAINTAINING YOUR VEHICLE

WARNING! (Continued)
•Do not allow petroleum based fluid to contami-
nate the brake fluid. Brake seal components could
be damaged, causing partial or complete brake
failure. This could result in a collision.
Automatic Transmission – If Equipped
Selection Of Lubricant
It is important that the proper lubricant is used in the
transmission to assure optimum transmission perfor-
mance. Use only manufacturer’s recommended transmis-
sion fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further informa-
tion. It is important that the transmission fluid be main-
tained at the prescribed level using the recommended
fluid.
CAUTION!
Using a transmission fluid other than the manufac-
turer’s recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
shudder. Using a transmission fluid other than the
manufacturer’s recommended fluid will require
more frequent fluid and filter changes. Refer to
“Fluids, Lubricants, and Genuine Parts” in “Main-
taining Your Vehicle” for further information.
Special Additives
Automatic Transmission Fluid (ATF) is an engineered
product and its performance may be impaired by supple-
mental additives. Therefore, do not add any fluid addi-
tives to the transmission. The only exception to this
policy is the use of special dyes to aid in detecting fluid
leaks. In addition, avoid using transmission sealers as
they may adversely affect seals.
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MAINTAINING YOUR VEHICLE 537

CAUTION!
Do not use chemical flushes in your transmission as
the chemicals can damage your transmission compo-
nents. Such damage is not covered by the New
Vehicle Limited Warranty.
Fluid Level Check
Check the fluid level while the transmission is at normal
operating temperature 180° F (82° C). This occurs after at
least 15 miles (25 km) of driving. At normal operating
temperature, the fluid cannot be held comfortably be-
tween the fingertips.
To properly check the automatic transmission fluid level,
the following procedure must be used:
1. Operate the engine at idle speed and normal operating
temperature.
2. The vehicle must be on level ground.3. Fully apply the parking brake.
4. Place the shift lever momentarily into each gear posi-
tion ending with the shift lever in PARK.
5. Remove the dipstick, wipe it clean and reinsert it until
seated.
6. Remove the dipstick again and note the fluid level on
both sides. The fluid level should be between the HOT
(upper) reference holes on the dipstick at normal operat-
ing temperature. Verify that a solid coating of oil is seen
on both sides of the dipstick. If the fluid is low, add as
required into the dipstick tube.
Do not overfill.After
adding any quantity of oil through the dipstick tube, wait
a minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.
NOTE: If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two cold (lower) holes on the dipstick with
538 MAINTAINING YOUR VEHICLE