2008 JEEP GRAND CHEROKEE engine

Fuel Filter
A plugged fuel filter can cause stalling, limit the speed at
which a vehicle can be driven or cause hard starting.
Should an excessive amount of dirt accumulate in the
fuel tank, filter replacement may be necessary. See your
local dealer for service.
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
catalyst as an emission control device.
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.
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 the
vehicle.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
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7

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 indicate severe
and abnormal catalyst overheating. If this occurs, the
vehicle should be stopped, the engine shut off and the
vehicle allowed to cool. Thereafter, service, including a
tune-up to manufacturer's specifications, should be ob-
tained immediately.To minimize the possibility of catalyst damage:²Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
²Do not try to start engine by pushing or towing the
vehicle.
²Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idling or malfunctioning operating conditions.
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.
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WARNING!
Fluid level should be checked on a level surface with
the engine off to prevent injury from moving parts,
and to insure accurate fluid level reading. Do not
overfill. Use only the manufacturer's recommended
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
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.
Body Lubrication
Locks and all body pivot points, including such items as
seat tracks, doors, trunk 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 insure 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 small
amount of a high quality MopartLock Cylinder Lubri-
cant or equivalent directly into the lock cylinder.
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7

Windshield Wiper Blades
The rubber edges of the wiper blades and the windshield
should be cleaned periodically with a sponge or soft cloth
and a mild nonabrasive cleaner. This will remove accu-
mulations 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.
Windshield Washers Ð Front and Rear
On vehicles equipped with a Electronic Vehicle Informa-
tion Center (EVIC), the low washer fluid level will be
indicated. When the sensor detects a low fluid level, the
windshield will light on the vehicle graphic outline andthe ªWasher Fluid Lowº message will be displayed. Refer
to ªElectronic Vehicle Information Centerº in Section 4 of
this manual.
The fluid reservoir for the windshield washers and the
rear window washer 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 antifreeze).
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 performance.
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.
322 MAINTAINING YOUR VEHICLE

WARNING!
Commercially available windshield washer solvents
are flammable. 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.Whenever a change is noticed in the sound of the exhaust
system, when exhaust fumes can be detected inside the
vehicle, or when the underside or rear of the vehicle is
damaged, have a competent mechanic inspect the com-
plete exhaust system and adjacent body areas for broken,
damaged, deteriorated, or mispositioned parts. Open
seams or loose connections could permit exhaust fumes
to seep into the passenger compartment. In addition,
inspect the exhaust system 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, fol-
low the preceding safety tips.
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7

Cooling System
WARNING!
²When working near the radiator cooling fan, dis-
connect the fan motor lead or turn the ignition
switch to the OFF position. The fan is temperature
controlled and can start at any time the ignition
switch is in the ON position.
²You or others can be badly burned by hot 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 is hot.
Coolant Checks
Check engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant. Check the front of the A/C condenser for any
accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the condenser.
Check the coolant recovery bottle tubing for brittle rub-
ber, cracking, tears, cuts and tightness of the connection
at the 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
coolant from the radiator drain cock. If the cap is sealing
properly, the engine coolant (antifreeze) will begin to
324 MAINTAINING YOUR VEHICLE

drain from the coolant recovery bottle. DO NOT RE-
MOVE THE COOLANT PRESSURE CAP WHEN THE
COOLING SYSTEM IS HOT.
Cooling System Ð Drain, Flush and Refill
At the intervals shown on the appropriate ªMaintenance
Schedule,º the system should be drained, flushed and
refilled.
If the solution 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 old
antifreeze solution.
Selection Of Coolant
Use only the manufacturer's recommended coolant, refer
to Fluids, Lubricants and Genuine Parts for correct
coolant type.
CAUTION!
Mixing of coolants other than specified HOAT en-
gine coolants, may result in engine damage and may
decrease corrosion protection. If a non-HOAT coolant
is introduced into the cooling system in an emer-
gency, it should be replaced with the specified cool-
ant as soon as possible.
Do not use plain water alone or alcohol base 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 coolants. Use of Propylene
Glycol based coolants is not recommended.
MAINTAINING YOUR VEHICLE 325
7

Adding Coolant
Your vehicle has been built with an improved engine
coolant that allows extended maintenance intervals. This
coolant can be used up to 5 Years or 100,000 miles (160
000 km) before replacement. To prevent reducing this
extended maintenance period, it is important that you
use the same coolant throughout the life of your vehicle.
Please review these recommendations for using Hybrid
Organic Additive Technology (HOAT) coolant.
When adding coolant:
²The manufacturer recommends using Mopart
Antifreeze/ Coolant 5 Year/100,000 Mile Formula
HOAT (Hybrid Organic Additive Technology)
²Mix a minimum solution of 50% HOAT engine coolant
and distilled water. Use higher concentrations (not to
exceed 70%) if temperatures below234ÉF (237ÉC ) are
anticipated.
²Use 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 coolant types will decrease the life of the
engine coolant and will require more frequent coolant
changes.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
coolant, and to insure that coolant will return to the
radiator from the coolant recovery bottle.
326 MAINTAINING YOUR VEHICLE