2008 JEEP GRAND CHEROKEE radiator

IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate ac-
tion.
²On the highways Ð Slow down.
²In city traffic Ð While stopped, put transmission in N
(Neutral), but do not increase engine idle speed.
NOTE:There are steps that you can take to slow down
an impending overheat condition. If your air conditioner
is on, turn it off. The air conditioning system adds heat to
the engine cooling system and turning off the A/C
removes this heat. You can also turn the Temperature
Control to maximum heat, the Mode Control to floor, and
the Fan Control to High. This allows the heater core to act
as a supplement to the radiator and aids in removing heat
from the engine cooling system.
CAUTION!
Driving with a hot cooling system could damage
your vehicle. If the temperature gauge reads ªHº,
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the ªHº, and you hear continuous chimes, turn the
engine off immediately, and call for service.
WHAT TO DO IN EMERGENCIES 299
6

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.
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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.
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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

The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
²The warning words ªDO NOT OPEN HOTº on
the cooling system pressure cap are a safety pre-
caution. Never add 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 scald-
ing or injury, do not remove the pressure cap while
the system is hot or under pressure.
²Do not use a pressure cap other than the one
specified for your vehicle. Personal injury or en-
gine damage may result.
Disposal of Used Engine Coolant
Used ethylene glycol based engine coolant is a regulated
substance requiring proper disposal. Check with your
local authorities to determine the disposal rules for your
community. To prevent ingestion by animals 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, contact a physician
immediately. Clean up any ground spills immediately.
Coolant Level
The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. With the
engine off and cold, the level of the 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
coolant freeze point or replacing coolant. Advise your
MAINTAINING YOUR VEHICLE 327
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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 coolant 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 (a
few kilometers) 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 accumulating on the radiator and being vapor-
ized when the thermostat opens, allowing hot 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.
²Do not overfill the coolant recovery bottle.
²Check coolant freeze point in the radiator and in the
coolant recovery bottle. If antifreeze needs to be
added, contents of coolant recovery bottle must also be
protected against freezing.
²If frequent coolant additions are required, or if the
level in the coolant recovery bottle does not drop when
the engine cools, the cooling system should be pres-
sure tested for leaks.
²Maintain coolant concentration at 50% HOAT engine
coolant (minimum) and distilled water for proper
corrosion protection of your engine which contains
aluminum components.
²Make sure that the radiator and coolant recovery
bottle overflow hoses are not kinked or obstructed.
328 MAINTAINING YOUR VEHICLE

²Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean, also.
²Do 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 coolant performance, poor gas
mileage, and increased emissions.
Hoses And Vacuum/Vapor Harnesses
Inspect surfaces of hoses and nylon tubing for evidence
of heat and mechanical damage. Hard or soft spots,
brittle rubber, cracking, tears, cuts, abrasions, and exces-
sive swelling indicate deterioration of the rubber.
Pay particular attention to those hoses nearest to high
heat sources such as the exhaust manifold. Inspect hose
routing to be sure hoses do not come in contact with any
heat source or moving component which may cause heat
damage or mechanical wear.Insure nylon tubing in these areas has not melted or
collapsed.
Inspect all hose connections such as clamps and cou-
plings to make sure they are secure and no leaks are
present.
Components should be replaced immediately if there is
any evidence of wear or damage that could cause failure.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Suggested service intervals can be found on the appro-
priate ªMaintenance Schedule.º Refer to Section 8 of this
manual.
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