2004 JEEP WRANGLER service schedule

Follow the recommended tire rotation frequency for your
type of driving found in the ªMaintenance Schedulesº
Section of this manual. More frequent rotation is permis-
sible if desired. The reasons for any rapid or unusual
wear should be corrected prior to rotation being per-
formed.
The suggested rotation method is the ªforward-crossº
shown in the following diagram.FUEL REQUIREMENTS
Your engine is designed to meet all emis-
sions regulations and provide excellent
fuel economy and performance when us-
ing high quality unleaded gasoline having
an octane rating of 87. The use of premium
gasoline is not recommended. The use of
premium gasoline will provide no benefit over high
quality regular gasoline, and in some circumstances may
result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Engine damage resulting from operation with a
heavy spark knock may not be covered by the new
vehicle warranty.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
STARTING AND OPERATING 197
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WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
Locking Fuel Filler Cap (Gas Cap) Ð If Equipped
²
Turn the engine off.
²Insert the ignition key into the fuel cap, and turn the
key to the right to unlock the fuel cap. Rotate the fuel
cap to the left to remove.
²To replace the cap, insert it into the filler neck and
tighten the cap about 1/4 turn until you hear one click.
This is an indication that the cap is properly tightened.
²Make sure that the fuel cap tether strap is not caught
under the fuel cap.
²Be sure to remove the key.
CAUTION!
To avoid fuel spillage and overfilling, do not ªtop
offº the fuel tank after filling.
NOTE:When the fuel nozzle ªclicksº or shuts off, the
fuel tank is full.
TRAILER TOWING
In this section you will find information on limits to the
type of towing you can reasonably do with your vehicle.
Before towing a trailer, carefully review this information
to tow your load as efficiently and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Perform maintenance services as prescribed in the
ªMaintenance Schedulesº section. When your vehicle is
used for trailer towing, never exceed the gross axle
weight rating (GAWR) by the addition of:
²The tongue weight of the trailer.
202 STARTING AND OPERATING

If your OBD system isnot ready,you should see your
authorized dealer or repair facility. If your vehicle was
recently serviced or had a battery failure or replacement,
you may need to do nothing more than drive your
vehicle as you normally would in order for your OBD
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD system is
ready or not ready, if the MIL symbol is illuminated
during normal vehicle operation, you should have your
vehicle serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL symbol is on
with the engine running.REPLACEMENT PARTS
Use of genuine Mopartparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Mopartparts for maintenance
and repairs will not be covered by the manufacturer's
warranty.
DEALER SERVICE
Your dealer has the qualified service personnel, special
tools and equipment to perform all service operations in
an expert manner. Service Manuals are available which
include detailed service information for your vehicle.
Refer to these manuals before attempting any procedure
yourself.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
MAINTAINING YOUR VEHICLE 227
7

CAUTION!
Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
²Day or night temperatures are below 32ÉF (0ÉC)
²Stop and go driving
²Extensive engine idling
²Driving in dusty conditions
²Short trip driving of less than 10 miles (16.2 km)
²More than 50% of your driving is at sustained high
speeds during hot weather, above 90ÉF (32ÉC)
²Taxi, Police, or delivery service (commercial service)
²Trailer towing
²Off-road or desert driving
²If equipped for and operating with E±85 (ethanol) fuel
IfANYof these apply to you, then change your engine oil
at every interval shown in schedule ªBº of the ªMainte-
nance Schedulesº section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule ªAº of the ªMain-
tenance Schedulesº section of this manual
NOTE:Under no circumstances should oil change
intervals exceed 6,000 miles (10 000 km) or 6 months
whichever comes first.
MAINTAINING YOUR VEHICLE 229
7

Materials Added To Engine Oils
The manufacturerstrongly recommendsagainst the ad-
dition of any additives (other than leak detection dyes) to
engine oil. Engine oil is an engineered product and it's
performance may be impaired by supplemental addi-
tives.
Disposing of Used Engine Oil
Care should be taken in disposing of used engine oil from
your vehicle. Used oil, indiscriminately discarded, can
present a problem to the environment. Contact your
authorized dealer, service station, or governmental
agency for advice on how and where used oil can be
safely discarded in your area.
Engine Oil Filter
The engine oil filter should be replaced at every engine
oil change.
Engine Oil Filter Selection
All of the manufacturer's engines have a full-flow type
disposable oil filter. Use a filter of this type for replace-
ment. The quality of replacement filters varies consider-
ably. Only high quality filters should be used to assure
most efficient service. Mopartengine oil filters are high
quality oil filters and are recommended.
Drive Belts Ð Check Condition and Tension
At the mileage shown in the appropriate ªMaintenance
Schedule,º check all drive belts for condition and proper
tension. Improper belt tension can cause belt slippage
and failure.
4.0L Engines
MAINTAINING YOUR VEHICLE 231
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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 ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing 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.
To minimize the possibility of catalytic converter dam-
age:
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 the 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.
²Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
²Do not allow vehicle to run out of fuel.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Engine Timing Belt Ð 2.4L Engine
Replace the engine timing belt at the intervals described
in the appropriate maintenance schedule.
Ignition Wiring System Ð 2.4L Engine
Replace the ignition cables at the intervals described in
the appropriate maintenance schedule.
MAINTAINING YOUR VEHICLE 233
7

If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to Recommended Fluids, Lubricants, and
Genuine Parts for correct fluid type.
Driveline And Steering Component Lubrication
U-joints (cardan joints) are sealed and do not require
lubrication. Prop shafts, yokes, ball joints and other
driveline and steering components may be provided with
grease fittings for lubrication. Lubrication of these com-
ponents at the intervals specified in the appropriate
ªMaintenance Scheduleº in Section 8 is very important,
particularly if your vehicle is subjected to off-road or
other heavy-duty use. See your authorized dealer for
complete service information.
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. Particularattention 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 lubricant such as MopartLock
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.
MAINTAINING YOUR VEHICLE 237
7

Pay particular attention to the hoses nearest to high heat
sources such as the exhaust manifold. Inspect hose rout-
ing to be sure hoses do not touch any heat source or
moving component that 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 couplings to make sure they are secure and no leaks
are present. Components should be replaced immedi-
ately if there is any evidence of degradation that could
cause failure.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the appropriate ªMaintenance Scheduleº in
Section 8 for suggested service intervals.
WARNING!
Riding the brakes can lead to brake failure and
possibly an accident. Driving with your foot resting
or riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You wouldn't have your full
braking capacity in an emergency.
Brake and Power Steering System Hoses
When servicing the vehicle for scheduled maintenance,
inspect surface of hoses for evidence of heat and me-
chanical damage. Hard and brittle rubber, cracking, tears,
cuts, abrasion, and excessive swelling suggest deteriora-
tion of the rubber. Particular attention should be made to
examining those hose surfaces nearest to high heat
sources, such as the exhaust manifold.
Inspect all hose clamps and couplings to make sure they
are secure and no leaks are present.
NOTE:Inspection of brake hoses should be done
whenever the brake system is serviced and every engine
oil change.
MAINTAINING YOUR VEHICLE 243
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