2013 JEEP WRANGLER UNLIMITED Owners Manual

into the passenger compartment. In addition, have the
exhaust system inspected each time the vehicle is raised
for lubrication or oil change. Replace as required.
WARNING!• Exhaust gases can injure or kill. They contain
carbon monoxide (CO), which is colorless and
odorless. Breathing it can make you unconscious
and can eventually poison you. To avoid breathing
CO, refer to “Safety Tips/Exhaust Gas” in “Things
To Know Before Starting Your Vehicle” for further
information.
• 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
exhaust system. Do not park or operate your ve-
hicle in areas where your exhaust system can con-
tact anything that can burn. CAUTION!• The catalytic converter requires the use of un-
leaded fuel only. Leaded gasoline will destroy the
effectiveness of the catalyst as an emissions control
device and may seriously reduce engine perfor-
mance and cause serious damage to the engine.
• Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition.
In the event of engine malfunction, particularly
involving engine misfire or other apparent loss of
performance, have your vehicle serviced promptly.
Continued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
7 MAINTAINING YOUR VEHICLE 575

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.576 MAINTAINING YOUR VEHICLE

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 (antifreeze). 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 verti-
cally down the face of the A/C condenser (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.
7 MAINTAINING YOUR VEHICLE 577

Cooling System – Drain, Flush, And Refill
If the engine coolant (antifreeze) is dirty or contains a
considerable amount of sediment, clean and flush with a
reliable cooling system cleaner. Follow with a thorough
rinsing to remove all deposits and chemicals. Properly
dispose of the old engine coolant (antifreeze) solution.
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Selection Of Coolant
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information. CAUTION!• Mixing of engine coolant (antifreeze) other than
specified Organic Additive Technology (OAT) en-
gine coolant (antifreeze), may result in engine
damage and may decrease corrosion protection.
Organic Additive Technology (OAT) engine cool-
ant is different and should not be mixed with
Hybrid Organic Additive Technology (HOAT) en-
gine coolant (antifreeze). If a non-OAT engine
coolant (antifreeze) is introduced into the cooling
system in an emergency, it should be replaced with
the specified engine coolant (antifreeze) as soon as
possible. (Continued)578 MAINTAINING YOUR VEHICLE

CAUTION! (Continued)• Do not use water alone or alcohol-based engine
coolant (antifreeze) products. Do not use additional
rust inhibitors or antirust products, as they may not
be compatible with the radiator engine coolant and
may plug the radiator.
• This vehicle has not been designed for use with
propylene glycol-based engine coolant (antifreeze).
Use of propylene glycol-based engine coolant (an-
tifreeze) is not recommended.
Adding 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 ten years or 150,000 miles (240,000 km) before replace-
ment. To prevent reducing this extended maintenance period, it is important that you use the same engine
coolant (antifreeze) throughout the life of your vehicle.
Please review these recommendations for using Organic
Additive Technology (OAT) engine coolant (antifreeze).
When adding engine coolant (antifreeze):
• The manufacturer recommends using MOPAR 
Antifreeze/Coolant 10 Year/150,000 Mile Formula
OAT (Organic Additive Technology) or equivalent.
• Mix a minimum solution of 50% OAT 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.
7 MAINTAINING YOUR VEHICLE 579

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 is not
recommended and can result in cooling system damage.
Drain, flush, and refill as soon as possible to avoid
damage if coolant types are mixed in an emergency.
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
recovery 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
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.
• Do not use a pressure cap other than the one
specified for your vehicle. Personal injury or en-
gine damage may result.580 MAINTAINING YOUR VEHICLE

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 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. 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.
7 MAINTAINING YOUR VEHICLE 581

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 expansion bottle.
• Check the coolant freeze point in the radiator and in
the coolant expansion bottle. If engine coolant (anti-
freeze) needs to be added, the contents of the coolant
expansion bottle must also be protected against
freezing.
• If frequent engine coolant (antifreeze) additions are
required, the cooling system should be pressure tested
for leaks. • Maintain engine coolant (antifreeze) concentration at
50% OAT engine coolant (antifreeze) (minimum) and
distilled water for proper corrosion protection of your
engine which contains aluminum components.
• Make sure that the coolant expansion bottle overflow
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 engine coolant (antifreeze)
performance, poor gas mileage, and increased emis-
sions.582 MAINTAINING YOUR VEHICLE