2008 JEEP WRANGLER engine

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 exhaust
system. Do not park or operate your vehicle in areas
where your exhaust system can contact anything 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.
MAINTAINING YOUR VEHICLE 387
7

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.
•Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
•Do not allow vehicle to run out of fuel.NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Crankcase Emission Control System
Proper operation of this system depends on freedom
from sticking or plugging due to deposits. As vehicle
mileage builds up, the PCV valve and passages may
accumulate deposits. If a valve is not working properly,
replace it with a new valve. DO NOT ATTEMPT TO
CLEAN THE OLD PCV VALVE!
Check ventilation hose for indication of damage or
plugging deposits. Replace if necessary.
Fuel Filter
A plugged fuel filter can cause hard starting or limit the
speed at which a vehicle can be driven. Should an
excessive amount of dirt accumulate in the fuel tank,
frequent replacement of the fuel filter which is mounted
in the fuel tank may be necessary.
388 MAINTAINING YOUR VEHICLE

Engine Air Cleaner Filter
Refer to the Maintenance Schedule in Section 8 for
recommended engine air cleaner filter change intervals.
WARNING!
The air cleaner can provide protection in the case of
engine backfire. Do not remove the air cleaner unless
it is necessary for repair or maintenance. Make sure
that no one is near the engine compartment before
starting the vehicle with the air cleaner removed.
Failure to do so can result in serious personal injury.
Maintenance-Free Battery
Your vehicle is equipped with a maintenance-free battery.
You will never have to add water, nor is periodic main-
tenance required.
WARNING!
Battery posts, terminals, and related accessories con-
tain lead and lead compounds. Always wash hands
after handling the battery.
CAUTION!
It is essential when replacing the cables on the
battery that the positive cable is attached to the
positive post and the negative cable is attached to the
negative post. Battery posts are marked (+) positive
and negative (-) and identified on the battery case.
Also, if a “fast charger” is used while battery is in the
vehicle, disconnect both vehicle battery cables before
connecting the charger to battery. Do not use a “fast
charger” to provide starting voltage.
MAINTAINING YOUR VEHICLE 389
7

NOTE:Use only manufacturer approved A/C System
Sealers, Stop Leak Products, Seal Conditioners, Compres-
sor Oil, and Refrigerants.
Refrigerant Recovery and Recycling
R-134a Air Conditioning Refrigerant is a hydrofluoro-
carbon (HFC) that is endorsed by the Environmental
Protection Agency (EPA) and is an ozone-saving product.
However, the manufacturer recommends that air condi-
tioning service be performed by authorized dealers or
other service facilities using recovery and recycling
equipment.
Power Steering Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises are
apparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through an autho-
rized DaimlerChrysler Dealership.
WARNING!
Fluid level should be checked on a level surface with
the engine off to prevent injury from moving parts,
and to ensure accurate fluid level reading. Do not
overfill. Use only the manufacturer’s recommended
power steering fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to Fluids, Lubricants, and Genuine Parts
in this section for correct fluid type.
NOTE: Upon initial start-up in cold weather, the power
steering pump may make noise for a short period of time.
This is due to the cold, thick fluid in the steering system.
This noise should be considered normal, and does not in
any way damage the steering system.
MAINTAINING YOUR VEHICLE 391
7

Driveline And Steering Component Lubrication
All driveline and steering components are sealed and do
not require lubrication. Driveshafts are not serviceable.
Body Lubrication
Locks and all body pivot points, including such items as
seat tracks, doors, tailgate and hood hinges, should be
lubricated periodically to assure quiet, easy operation
and to protect against rust and wear. Prior to the appli-
cation of any lubricant, the parts concerned should be
wiped clean to remove dust and grit; after lubricating
excess oil and grease should be removed. Particular
attention should also be given to hood latching compo-
nents to ensure proper function. When performing other
underhood services, the hood latch, release mechanism
and safety catch should be cleaned and lubricated.
The external lock cylinders should be lubricated twice a
year, preferably in the Fall and Spring. Apply a smallamount of a high quality lubricant such as MOPAR
Lock Cylinder Lubricant directly into the lock cylinder.
Windshield Wiper Blades
Clean the rubber edges of the wiper blades and the
windshield periodically with a sponge or soft cloth and a
mild non-abrasive cleaner. This will remove accumula-
tions of salt or road film.
Operation of the wipers on dry glass for long periods
may cause deterioration of the wiper blades. Always use
washer fluid when using the wipers to remove salt or dirt
from a dry windshield. Avoid using the wiper blades to
remove frost or ice from the windshield. Keep the blade
rubber out of contact with petroleum products such as
engine oil, gasoline, etc.
392 MAINTAINING YOUR VEHICLE

Windshield And Rear Window Washers
The fluid reservoir for the windshield washers and the
rear window washer (if equipped) is shared. The fluid
reservoir is located in the engine compartment. Be sure to
check the fluid level at regular intervals. Fill the reservoir
with windshield washer solvent only (not radiator anti-
freeze). When refilling the washer fluid reservoir, take
some washer fluid and apply it to a cloth or towel and
wipe clean the wiper blades, this will help blade perfor-
mance.
To prevent freeze-up of your windshield washer system
in cold weather, select a solution or mixture that meets or
exceeds the temperature range of your climate. This
rating information can be found on most washer fluid
containers.WARNING!
Commercial windshield washer solvents are flam-
mable. They could ignite and burn you. Care must be
exercised when filling or working around the washer
solution.
Exhaust System
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system.
If you notice a change in the sound of the exhaust system;
or if the exhaust fumes can be detected inside the vehicle;
or when the underside or rear of the vehicle is damaged;
have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seep
MAINTAINING YOUR VEHICLE 393
7

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