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NOTE:High-speed, no-load running of a cold engine can
result in excessive white smoke and poor engine perfor-
mance. No-load engine speeds should be kept under
1,200 RPM during the warm-up period, especially in cold
ambient temperature conditions.
Your vehicle is equipped with a turbo speed limiter, this
feature limits the engine speed to 1,200 RPM when
engine coolant temperatures are below 70°F (21°C). This
feature is designed to protect the turbocharger from
damage and will only operate in PARK or NEUTRAL.
If temperatures are below 32°F (0°C), operate the engine
at moderate speeds for five minutes before full loads are
applied. NOTE:
If ambient temperatures are low and the coolant
temperature is below 180°F (82°C), the engine idle speed
will slowly increase to 1,000 RPM after two minutes of
idle, if the following conditions are met:
• Foot is off brake pedal and throttle pedal.
• Automatic transmission is in PARK.
• Vehicle speed is 0 mph (0 km/h).
• Applying the throttle will cancel fast idle.
• Operating the exhaust brake at idle will greatly im-
prove warm up rate and will help keep the engine
close to operating temperature during extended idle.
Engine Idling
Avoid prolonged idling, long periods of idling may be
harmful to your engine because combustion chamber
temperatures can drop so low that the fuel may not burn
completely. Incomplete combustion allows carbon and
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Stopping The Engine
Idle the engine a few minutes before routine shutdown.
After full load operation, idle the engine three to five
minutes before shutting it down. This idle period will
allow the lubricating oil and coolant to carry excess heat
away from the combustion chamber, bearings, internal
components, and turbocharger. This is especially impor-
tant for turbocharged, charge air-cooled engines.NOTE:
•
During engine shut down on vehicles equipped with
manual transmissions, it is normal for the diesel en-
gine to resonate heavily for a moment during engine
shut off. When the engine is connected to a manual
transmission, this resonance causes load gear rattle
from the transmission. This is commonly referred to as
“shut down rattle.” The manufacturer recommends
performing engine shut down with the clutch pedal
pushed to the floor (clutch disengaged). When engine
shut down is performed in this manner the rattle is
reduced (not eliminated).
• Refer to the following chart for proper engine shut-
down.
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Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (antifreeze) (a
mixture of 50% ethylene-glycol and 50% water) must not
exceed the normal range of the temperature gauge 240°F
(116°C) with a 21 psi (145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze) temperature indi-
cated during operation will be to the left of center in the
normal range of the gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant (antifreeze)
temperature below the normal range on the gauge 140°F
(60°C) can be harmful to the engine. Low engine coolant
(antifreeze) temperature can cause incomplete combus-
tion which allows carbon and varnish to form on pistonrings and injector nozzles. Also, the unburned fuel can
enter the crankcase, diluting the lubricating oil and
causing rapid wear to the engine.
Cooling System Tips — Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
•
City Driving —
When stopped, shift the transmission into NEUTRAL
and increase engine idle speed.
• Highway Driving —
Reduce your speed.
• Up Steep Hills —
Select a lower transmission gear.
• Air Conditioning —
Turn it off temporarily.
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Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM 10 psi (69 kPa)
Full speed and load 30 psi (207 kPa)
CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage.
Do Not Operate The Engine With Failed Parts
All engine failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:•
Engine misfiring or vibrating severely.
• Sudden loss of power.
• Unusual engine noises.
• Fuel, oil or coolant leaks.
• Sudden change, outside the normal operating range, in
the engine operating temperature.
• Excessive smoke.
• Oil pressure drop.
ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the heater
cord to a ground-fault interrupter protected 110–115 Volt
AC electrical outlet with a grounded, three-wire exten-
sion cord.
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The engine block heater cord is routed under the hood to
the right side and can be located just behind the grille
near the headlamp.
NOTE:The engine block heater cord is a factory installed
option. If your vehicle is not equipped, heater cords are
available from your authorized MOPAR dealer.
The block heater must be plugged in at least one hour to
have an adequate warming effect on the coolant.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110–115 Volt electrical cord could
cause electrocution.
NOTE: The block heater will require 110 Volts AC and 6.5
Amps to activate the heater element.
Block Heater Usage
For ambient temperatures below 0°F (-18°C), engine
block heater usage is recommended.
For ambient temperatures below –20°F (-29°C), engine
block heater usage is required.
DIESEL EXHAUST BRAKE (ENGINE BRAKING)
The purpose of the exhaust brake (engine braking) fea-
ture is to supply negative (braking) torque from the
engine. Typically, the engine braking is used for, but not
limited to, vehicle towing applications where vehicle
braking can be achieved by the internal engine power,
thereby sparing the mechanical brakes of the vehicle.
Benefits of the exhaust brake are:
• Vehicle driving control.
• Reduced brake fade.
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The automatic transmission will downshift more aggres-
sively in TOW/HAUL mode when the exhaust brake is
enabled to increase brake performance.
CAUTION!
Use of aftermarket exhaust brakes is not recom-
mended and could lead to engine damage
WARNING!
Do not use the exhaust brake feature when driving in
icy or slippery conditions as the increased engine
braking can cause the rear wheels to slide and the
vehicle to swing around with the possible loss of
vehicle control, which may cause an accident possi-
bly resulting in personal injury or death.
NOTE: For optimum braking power it is recommended
to use the exhaust brake while in TOW/HAUL mode. The exhaust brake feature can also be used to reduce the
engine warm up time. To use the exhaust brake as a
warm-up device, the vehicle must be stopped or moving
less than 5 mph (8 km/h), the
Exhaust Brake Indicator
must be on, and the coolant temperature must be below
180°F (82°C) and ambient temperature below 60°F (16°C).
Automatic Smart Exhaust Brake
Automatic Exhaust Brake technology delivers smoother,
less aggressive exhaust braking characteristics during
downhill descents. Although it can apply full exhaust
braking force if needed, Automatic Exhaust Brake may
not apply obvious braking if the vehicle speed is not
increasing. Automatic Exhaust Brake is intended to main-
tain vehicle speed, while Full Exhaust Brake is intended
to reduce vehicle speed.
Automatic Exhaust Brake can be enabled by pushing the
exhaust brake button again anytime after the normal Full
Exhaust Brake has been turned on. The “Exhaust Brake
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CAUTION!
When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The trans-
mission will automatically shift into Overdrive if the
following conditions are present:
•The shift lever is in the DRIVE position.
• The transmission fluid has reached an adequate tem-
perature.
• The engine coolant has reached an adequate tempera-
ture. •
The vehicle speed is sufficiently high.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the TOW/HAUL switch to activate TOW/
HAUL mode. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting. When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the trans-
mission will automatically downshift (for engine brak-
ing) when the throttle is closed and/or during steady
braking maneuvers.
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NOTE:
•The torque converter clutch will not engage (and
68RFE-equipped trucks will not shift to sixth gear),
until the transmission fluid and engine coolant are
warm [usually after 1 to 3 miles (2 to 5 km) of driving].
Because the engine speed is higher when the torque
converter clutch is not engaged, it may seem as if the
transmission is not shifting properly when cold. This is
normal. Using the Electronic Range Select (ERS) shift
control, when the transmission is sufficiently warm,
will demonstrate that the transmission is able to shift
into and out of Overdrive.
•
If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the transmis-
sion into gear may seem sluggish. This is due to the fluid
partially draining from the torque converter into the
transmission. This condition is normal and will not cause damage to the transmission. The torque converter will
refill within five seconds after starting the engine.
MANUAL TRANSMISSION — IF EQUIPPED
WARNING!
You or others could be injured if you leave the
vehicle unattended without having the parking
brake fully applied. The parking brake should al-
ways be applied when the driver is not in the vehicle,
especially on an incline.
CAUTION!
Never drive with your foot resting on the clutch
pedal, or attempt to hold the vehicle on a hill with the
clutch pedal partially engaged, as this will cause
abnormal wear on the clutch.
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