2004 DODGE DURANGO engine

ONBOARD DIAGNOSTIC SYSTEM Ð OBD II
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the ªMalfunction Indicator Light.º It will
also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your dealer for service as soon as
possible.CAUTION!
²Prolonged driving with the ªMalfunction Indica-
tor Lightº on could cause further damage to the
emission control system. It could also affect fuel
economy and driveability. The vehicle must be
serviced before any emissions tests can be per-
formed.
²If the ªMalfunction Indicator Lightº is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
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EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass
an inspection of your vehicle's emissions control system.
Failure to pass could prevent vehicle registration.
For states which have an I/M (Inspection and
Maintenance) requirement, this check verifies the
following: the MIL (Malfunction Indicator Lamp)
is functioning and is not on when the engine is running,
and that the OBD (On Board Diagnostic) system is ready
for testing.
Normally, the OBD system will be ready. The OBD
system maynotbe ready if your vehicle was recently
serviced, if you recently had a dead battery, or a battery
replacement. If the OBD system should be determined
not ready for the I/M test, your vehicle may fail the test.Your vehicle has a simple ignition key actuated test
which you can use prior to going to the test station. To
check if your vehicle's OBD system is ready, you must do
the following:
1. Insert your ignition key into the ignition switch.
2. Turn the ignition to the ON position, but do not crank
or start the engine.
3. If you crank or start the engine, you will have to start
this test over.
4. As soon as you turn your key to the ON position, you
will see your MIL symbol come on as part of a normal
bulb check.
5. Approximately 15 seconds later, one of two things will
happen:
a. The MIL light will blink for approximately 5 sec-
onds and then remain on until the first engine crank or
290 MAINTAINING YOUR VEHICLE

the key is turned off. This means that your vehicle's
OBD system isnot readyand you shouldnotproceed
to the I/M station.
b. The MIL light will remain fully illuminated until the
first engine crank or the key is turned off. This means
that your vehicle's OBD system isreadyand you can
proceed to the I/M station.
If your OBD system isnot ready,you should see your
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 yourvehicle 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.
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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 Engine Oil Level
To assure proper lubrication of your vehicle's engine, the
engine oil must be maintained at the correct level. The
best time to check the engine oil level is about 5 minutes
after a fully warmed up engine is shut off or before
starting the engine after it has sat overnight.
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1. Position the vehicle on a level surface.
2. Turn Off the engine and allow approximately 5 min-
utes for the oil to settle to the bottom of the crankcase.
3. Remove the engine oil level indicator (dipstick).
4. Wipe the engine oil level indicator (dipstick) clean.
5. Install the engine oil level indicator (dipstick) and
make sure it is seated in the tube.
6. Remove the engine oil level indicator (dipstick), keep-
ing the handle above the tip, and read the oil level on the
engine oil level indicator (dipstick).
7. Add oil only if the level is below the ªSAFEº range (at
or below the ªADDº mark) on the engine oil level
indicator (dipstick). Adding one quart of oil when the
reading is at the ADD mark will result in a SAFE reading
on these engines.
CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could dam-
age your engine.
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Frequency Of Oil Change
Road conditions and your style of driving affect the
interval at which your oil should be changed. Check the
following to determine ifANYapply to you:
²Day or night temperatures are below 32ÉF (0ÉC).
²Stop and Go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips 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).
²Trailer towing, Taxi, Police or delivery service (com-
mercial service).
²Off-Road or desert operation.
²If equipped for and operating with E-85 (ethanol)
fuel.
NOTE:IfANYof these apply to you then change your
engine oil every 3,000 miles (5 000 km) or 3 months,
whichever comes first and follow schedule ªBº of the
9Maintenance Schedules9section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule9A9of the9Mainte-
nance Schedules9section of this manual.
4x4 Models, If Used Primarily For Off-Road Operation
Every 50 hours of use.
Dusty Conditions
Driving through dust-laden air increases the problems of
keeping abrasive materials out of the engine. Under these
conditions, special attention should be given to the
engine air cleaner and the crankcase inlet air cleaner. The
crankcase ventilation system should also be checked
294 MAINTAINING YOUR VEHICLE

periodically. Make sure that these units are always clean.
This will tend to reduce to a minimum the amount of
abrasive material that may enter the engine.
Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacture only
recommends engine oils that are API certified and meet
the requirements of DaimlerChrysler Material Standard
MS-6395. Use Mopar or an equivalent oil meeting the
specification MS-6395.
Engine Oil Identification (API) Symbol
There is a symbol to aid you in selecting the proper
engine oil.This symbol means that the oil has
been certified by the American
Petroleum Institute (API). The
manufacture only recommends
API Certified engine oils that
meet the requirements of
DaimlerChrysler Material Stan-
dard MS-6395. Use Mopar or an
equivalent oil meeting the specifi-
cation MS-6395.
Engine Oil Viscosity Chart
The proper SAE viscosity grade of engine oil should be
selected based on the following recommendation and be
within the operating temperature shown in the recom-
mended SAE viscosity chart.
²SAE 5W-30 is the preferred oil for Dodge Trucks with
3.7L/4.7L/5.7L engines. Synthetic engine oils may be
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used provided that the oil quality requirements de-
scribed above are met and the recommended mainte-
nance intervals for oil and filter changes are followed.
²Lubricants which do not have both the engine oil
certification mark or current service symbol and the
correct viscosity grade number should not be used.
Synthetic Engine Oils
There are a number of engine oils being promoted as
either synthetic or semi-synthetic. If you chose to use
such a product, useonlythose oils that meet the Ameri-
can Petroleum Institute (API) and SAE viscosity stan-
dard. Follow the service schedule that describes your
driving type.
Materials Added to Engine Oils
The manufacture strongly recommends against the addi-
tion of any additives (other than leak detection dyes) to
the engine oil. Engine oil is an engineered product and
it's performance may be impaired by supplemental ad-
ditives.
Disposing of Used Engine Oil And Oil Filters
Care should be taken in disposing of used engine oil and
oil filters from your vehicle. Used oil and oil filters,
indiscriminately discarded, can present a problem to the
environment. Contact your dealer, service station, or
Preferred Viscosity for 3.7L/4.7L/5.7L Engines
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