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ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine in
your new vehicle.
Drive moderately during the first 300 miles (500 km).
After the initial 60 miles (100 km), speeds up to 50 or 55
mph (80 or 90 km/h) are desirable.
While cruising, brief full-throttle acceleration, within the
limits of local traffic laws, contributes to a good break-in.
Wide open throttle acceleration in low gear can be
detrimental and should be avoided.
The engine oil installed in the engine at the factory is a
high quality energy conserving type lubricant. Oil
changes should be consistent with anticipated climate
conditions under which vehicle operations will occur.
The recommended viscosity and quality grades are
shown in Section 7 of this manual. NON-DETERGENT
OR STRAIGHT MINERAL OILS MUST NEVER BE
USED.A new engine may consume some oil during its first few
thousand miles (kilometers) of operation. This should be
considered as a normal part of the break-in and not
interpreted as an indication of difficulty.
SAFETY TIPS
Exhaust Gas
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)
follow the safety tips below.
²Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 51
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7. Oil Pressure Gage
Indicates the engine oil pressure. This gage does
not measure oil level. Pressure varies with engine
speed, temperature, and oil viscosity. Normal oil pressure
will be midway between the lowest and highest limit
marks.
8. Sentry Key Indicator Light Ð If Equipped
Refer to ªSentry Key Immobilizer Systemº in
Section 2 of this manual for more information.
9. Malfunction Indicator Light
This light is part of an onboard diagnostic system
called OBD II which monitors engine and auto-
matic transmission control systems. This light
will illuminate when the ignition is in the ON position
before engine start. If the bulb does not come on when
turning the ignition key from OFF to ON, have the
condition checked promptly.Certain conditions such has a loose or missing gas cap,
poor fuel quality, etc. may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several typical driving cycles. In most
situations, the vehicle will drive normally and will not
require towing.
When the engine is running, the ªMalfunction Indicator
Lightº may flash to alert of serious conditions that could
lead to immediate loss of power or severe catalytic
converter damage. The vehicle should be serviced as
soon as possible if this occurs.
10. Cruise Indicator Light
This indicator lights when the electronic speed
control system is turned ON.
11. Check Gages Warning Light
This light illuminates when the voltmeter, oil
pressure, or temperature gages indicate a reading
130 UNDERSTANDING YOUR INSTRUMENT PANEL
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either too high or too low. Examine the gages carefully,
and follow the instructions above for each indicated
problem.
NOTE:When the ignition switch is turned to OFF, the
fuel gage, voltmeter, oil pressure, and temperature gages
will not show any readings. When the engine is not
running, turn the ignition switch to ON to obtain accu-
rate readings.
12. Part Time Indicator Light
This light alerts the driver that the vehicle is in
the PART TIME four±wheel drive mode, and
the front and rear driveshafts are mechanically
locked together forcing the front and rear wheels to rotate
at the same speed.
13. Transmission Over Temperature Warning Light
This light indicates that there is excessive transmis-
sion fluid temperature that might occur with severe
usage such as trailer towing or snow plowing. If this lightcomes on, stop the vehicle and run the engine at idle or
faster, with the transmission in N (Neutral) until the light
goes off.
14. Temperature Gage
Indicates engine coolant temperature. Any read-
ing within the normal range indicates that the
cooling system is operating satisfactorily.
The gage pointer will likely indicate a higher temperature
(above center scale) when driving in hot weather, up
mountain grades, or when towing a trailer. It should not
be allowed to exceed the upper limits of the normal
operating range.
If the pointer rises to the 260É (Hot) mark, pull over and
stop the vehicle. Do not turn the engine off. Idle the
vehicle with the air conditioning turned off, until the
pointer drops back into the normal range.
UNDERSTANDING YOUR INSTRUMENT PANEL 131
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After Starting
The idle speed will automatically decrease as the engine
warms up.
CAUTION!
Long periods of engine idling, especially at high
engine speeds can cause excessive exhaust tempera-
tures which can damage your vehicle. Do not leave
your vehicle unattended with the engine running.
ENGINE BLOCK HEATER Ð IF EQUIPPED
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the cord
to a standard 110-115 volt AC electrical outlet with
grounded, three wire extension cord.
Use the heater when temperatures below 0ÉF (-18ÉC) are
expected to last for several days.The engine block heater cord is located:
²6-cylinder engine Ð bundled and fastened to the
injector rail between injectors 1 and 2.
²V-8 engine Ð coiled and strapped to the transmission
filler tube.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110-115 volt AC electrical cord could
cause electrocution.
178 STARTING AND OPERATING
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Over Temperature Mode
The transmission electronics constantly monitor the
transmission oil temperature. If the transmission gets too
hot, the transmission will change the way it shifts to help
control the condition. This may result in a slightly
different feeling or response during normal operation in
D (Drive) position. If the transmission becomes hot
enough the O/D OFF indicator light and TRANS OVER
TEMP warning light in the instrument cluster may come
on. After the transmission cools down, it will return to
normal operation.
Torque Converter Clutch
A feature designed to improve fuel economy has been
added to the automatic transmission of this vehicle. A
clutch within the torque converter engages automatically
at calibrated speeds. This may result in a slightly differ-
ent feeling or response during normal operation in high
gear. When the vehicle speed drops or during accelera-
tion, the clutch automatically and smoothly disengages.NOTE:
²The torque converter clutch will not engage until the
transmission fluid and engine coolant are warm (usu-
ally after 1±3 miles (1.6±4.8 km) of driving). Because
engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmis-
sion is not shifting into ªOverdriveº when cold. This is
considered a normal condition. Pressing the ªO/D
OFFº switch will show that the transmission is able to
shift into and out of ªOverdrive.º
²If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
transmission fluid partially draining from the torque
converter into the transmission. This is considered a
normal condition and will not cause damage to the
transmission. The torque converter will refill within 5
seconds of shifting from P (Park) into any other gear
position.
STARTING AND OPERATING 185
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MAINTAINING YOUR VEHICLE
CONTENTS
m4.0L Engine...........................251
m4.7L/4.7 HO Engine.....................252
mOnboard Diagnostic System Ð OBD II........253
mEmissions Inspection And Maintenance
Programs............................254
mReplacement Parts......................255
mDealer Service.........................255
mMaintenance Procedures..................256
NEngine Oil..........................256NDrive Belts - Check Condition And Tension . . . 261
NSpark Plugs.........................261
NCatalytic Converter....................261
NCrankcase Emission Control System........263
NFuel Filter..........................263
NAir Cleaner Filter.....................264
NMaintenance-Free Battery................264
NAir Conditioner Maintenance.............265
NPower Steering Fluid Check..............266
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NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
WARNING!
You can be badly injured working on or around a
motor vehicle. Do only that service work for which
you have the knowledge and the proper equipment.
If you have any doubt about your ability to perform
a service job, take your vehicle to a competent
mechanic.
MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, it
could adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
Engine Oil
Checking Oil Level
To assure proper engine lubrication, the engine oil must
be maintained at the correct level. Check the oil level at
regular intervals, such as every fuel stop.
256 MAINTAINING YOUR VEHICLE
Page 257 of 344
The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level between the MIN and MAX or ADD and
SAFE markings on the dipstick. Adding 1 U.S. Quart
(0.95L) of oil when the reading is at the MIN mark will
result in a MAX reading on these engines.
4.0L Engines
4.7L Engines
MAINTAINING YOUR VEHICLE 257
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