Page 171 of 264

ignition key or start the engine. This means that your
vehicle’s OBD system isnot readyand you shouldnot
proceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn off the ignition key or start
the engine. 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
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 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 Moparparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Moparparts 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.
MAINTAINING YOUR VEHICLE 171
7
Page 172 of 264

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 the maintenance service
recommendations 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 lubrication of your vehicle’s engine, the
engine oil must be maintained, at the correct level. Check
the oil level at regular intervals, such as every fuel stop.
172 MAINTAINING YOUR VEHICLE
Page 173 of 264

The best time to check the oil level is approximately 5
minutes after a fully warmed up engine is turned off or
before starting the engine after it has sat overnight.
Checking the oil while the vehicle is on level ground also
will improve the accuracy of the oil level readings. Add
oil only when the level is below the SAFE mark.Changing Engine Oil
Road conditions and your kind of driving affects the
interval at which your oil should be changed.
IfANYof the following apply to you, then change your
engine oil every 3,000 miles (5 000 km) or 3 months,
whichever comes first and follow the maintenance rec-
ommendations in ScheduleB.
•Day or night temperatures are below 32°F (0°C)
•Stop and go driving
•Extensive engine idling
•Driving in dusty conditions
•Short trip driving of less than 10 miles (16.2 km)
•More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
•Taxi, Police, or delivery service (commercial service)Engine Oil Dipstick
MAINTAINING YOUR VEHICLE 173
7
Page 174 of 264

•Trailer towing
•Off-road or desert driving
•If equipped for and operating with E–85 (ethanol) fuel
If none of these apply to you, then change your engine oil
every 6,000 miles (10 000 km) or 6 months, whichever
comes first and follow the maintenance recommenda-
tions in ScheduleA.
CAUTION!
Overfilling the crankcase will cause oil aeration and
loss of oil pressure. This could damage your engine.
Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacturer only
recommends full synthetic engine oils that are API rated
as SL/CF and meet the requirements of DaimlerChrysler
Material Standard MS-10725. Use Mopar or an equivalent
oil meeting the specification MS-10725.
If you choose to operate this vehicle in a very aggres-
sive driving style, the manufacturer recommends the
use of a full synthetic engine oil, such as Mobil 1SAE
0W-40.
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 engine oil
viscosity chart.
174 MAINTAINING YOUR VEHICLE
Page 175 of 264

Materials Added to Engine Oil
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
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
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 with a new filter
at every engine oil change.
Engine Oil Filter Selection
All manufacturer’s engines have a full-flow type dispos-
able oil filter. Use a filter of this type for replacement. The
quality of replacement filters varies considerably. Only
high quality filters should be used to assure most efficient
service. Moparengine oil filters are high quality oil
filters and are recommended.
MAINTAINING YOUR VEHICLE 175
7
Page 176 of 264

Drive Belts — Check Condition and Tension
At the mileage shown in the appropriate “Maintenance
Schedule”, check the condition of the drive belt for
condition and proper tension. Improper belt tension can
cause belt slippage and failure.
Inspect the drive belt for evidence of cuts, cracks, or
glazing and replace it if there is any sign of damage
which could result in belt failure.
Spark Plugs
Spark plugs must fire properly to assure proper engine
performance and emission control. Install new recom-
mended plugs with the recommended gap at the speci-
fied mileage.
Refer to the “Vehicle Emission Control Information” label
in the engine compartment for spark plug information.
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.
176 MAINTAINING YOUR VEHICLE
Page 177 of 264

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.
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 manufacturers specifica-
tions, should be obtained immediately.
MAINTAINING YOUR VEHICLE 177
7
Page 178 of 264

To minimize the possibility of catalytic converter dam-
age:
•Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
•Do not try to start the engine by pushing or towing the
vehicle.
•Do not idle the engine with any spark plug wires
disconnected for prolonged period.
Ignition Wiring System and Ignition Timing
The ignition cables should be kept clean and properly
connected. Terminals should be fully seated. Do not
remove the nipple assemblies from the coil towers unless
the nipples are damaged or cable testing shows high
resistance or broken insulation. Refer to the ServiceManual for the proper procedure to be followed for
checking ignition cable resistance. Cracked, damaged, or
faulty cables should be replaced.
Because of the plastic body shell on your Viper, ignition
cables should be replaced with the specially designed RFI
cables available at your dealer.
Ignition timing cannot be set on this vehicle.
Crankcase Emission Control System
Proper operation of this system depends on freedom
from plugging due to deposits. As vehicle mileage builds
up, the Crankcase Ventilation Valve orifice may accumu-
late deposits. If a valve is not working properly, replace it
with a new orifice. DO NOT ATTEMPT TO CLEAN THE
OLD ORIFICE!
Check the ventilation hose for indication of damage or
plugging deposits. Replace if necessary.
178 MAINTAINING YOUR VEHICLE