2008 DODGE RAM 3500 CHASSIS CAB engine coolant

²Allow the engine to idle about three minutes until
the manifold heaters have completed the post-heat
cycle.
²Release the parking brake and drive.
NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
NOTE:If the engine stalls or if the ignition switch is left
On for more than 2 minutes after the WAIT TO START
light goes out, reset the grid heaters by turning the
ignition switch to Off for at least 5 seconds and then back
On. Repeat steps 3 through 7 of the normal starting
procedure.
For Extremely Cold Weather Starting Ð Engine
Manifold Air Temperature Below 0ÉF (- 18ÉC)
In extremely cold weather below 0ÉF (- 18ÉC) it may be
beneficial to cycle the manifold heaters twice before
attempting to start the engine. This can be accomplished
by turning the ignition OFF for at least 5 seconds and
then back ON after the WAIT TO START light has gone
off, but before the engine is started. However, repeated
cycling of the manifold heaters will result in damage to
the heater elements or reduced battery voltage.
NOTE: If multiple pre-heat cycles are used before
starting, additional engine run time may be required to
maintain battery state of charge at a satisfactory level.
²If the engine stalls after the initial start, the ignition
must be turned to the OFF position for at least 5
seconds and then to the ON position to recycle the
manifold heaters.
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5

NOTE:Excessive white smoke and poor engine perfor-
mance will result if manifold heaters are not recycled.
²Heat generated by the manifold heaters dissipates
rapidly in a cold engine. If more than two minutes
pass between the time the WAIT TO START light goes
OFF and the engine is started, recycle the manifold
heaters by turning the ignition OFF for at least 5
seconds and then back ON.
²If the vehicle is driven and vehicle speed exceeds 19
mph (31 km) before the manifold heater post-heat
(after start) cycle is complete, the manifold heaters will
shut off.
²If the engine is started before the WAIT TO START
light turns off, the preheat cycle will turn off.
²If the engine is cranked for more than 10 seconds, the
post-heat cycle will turn off.NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
NOTE:When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air is pulled into
the fuel system.
You may try priming as described below.
1. Add a substantial quantity of fuel to the tank (5 to 10
gallons) or eliminate the gelled fuel condition.
2. Crank the engine for 1 to 2 seconds. If the engine does
not start, then release the key or starter button back to the
RUN position (do not turn the key back to the OFF
position). The electric fuel transfer pump will continue to
run and purge air from the system for about 20 seconds.
After 20 seconds, attempt to start the engine again.
3. Start the engine using the Normal Starting Procedure.
260 STARTING AND OPERATING

Engine Block Heater
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.
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 in-
stalled option. If your vehicle is not equipped, heater
cords are available from your authorized Mopartdealer.
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
A.Temperatures below 0ÉF (-18ÉC)
²Block Heater Required for 15W-40
²Block Heater Recommended for 5W-40
B.Temperatures below - 20ÉF (-29ÉC)
²Block Heater Required for 5W-40
264 STARTING AND OPERATING

If temperatures are below 32ÉF (0ÉC), operate the engine
at moderate speeds for 5 minutes before full loads are
applied.
Engine Idling Ð In Cold Weather
Avoid prolonged idling in ambient temperatures below
0ÉF. 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 varnish to
form on piston rings and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting the oil
and causing rapid wear to the engine. Excessive idle time
can also cause damage to the engine exhaust aftertreat-
ment system.
NOTE:An optional driver-controlled high idle speed is
available on automatic transmission equipped vehicleswith speed control. This feature allows the driver to
select an elevated idle speed between 1100 and 1500
rpms. Your dealer can enable this feature.
NOTE:²If ambient temperatures are low and the coolant
temperature is below 200ÉF (93ÉC), the engine idle
speed will slowly increase to 1000 RPM after 2 minutes
of idle, if the following conditions are met:
²foot is off brake pedal and throttle pedal
²automatic transmission is in Park (P)
²vehicle speed is zero
²Applying the throttle will cancel fast idle
²If the engine is equipped with an exhaust brake,
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.
266 STARTING AND OPERATING

Stopping The Engine
Idle the engine a few minutes before routine shutdown.
After full load operation, idle the engine 3 to 5 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 important for turbo-
charged, charge air cooled engines.
NOTE:During engine shut down on vehicles equipped
with manual transmissions, it is normal for the diesel
engine 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 ªshut
down rattleº. 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).Driving
ConditionLoadTurbo-
charger
TemperatureIdle Time
(min.) Be-
fore Engine
Shutdown
Stop and
GoEmpty Cool Less than
One
Stop and
GoMedium One
Highway
SpeedsMedium Warm Two
City Traffic Maximum
GCWRThree
Highway
SpeedsMaximum
GCWRFour
Uphill
GradeMaximum
GCWRHot Five
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5

Engine Speed Control
CAUTION!
Prevent overspeeding the engine going down hill.
When descending steep grades, use a combination of
gears and service brakes to control vehicle/engine
speed. Overspeed can cause severe engine damage.
Operating Precautions
Avoid Overheating The Engine
The temperature of the coolant (a mixture of 50%
ethylene-glycol and 50% water) must not exceed the
normal range of the temperature gauge (240ÉF/116ÉC)
with a 16 psi (110 kPa) radiator cap.
Usually the coolant temperature indicated during opera-
tion will be to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low coolant temperature below
the normal range on the gauge (140ÉF/60ÉC) can be
harmful to the engine. Low coolant temperature can
cause incomplete combustion which allows carbon and
varnish to form on piston rings 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 Ð Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
²City Driving Ð
when stopped, put transmission in neutral and increase
engine idle speed.
²Highway Driving Ð
reduce your speed.
268 STARTING AND OPERATING

²Up Steep Hills Ð
select a lower transmission gear, but try and keep the
torque converter clutch engaged.
²Air Conditioning Ð
turn it off temporarily.
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............... 10psi(69kPa)
Full speed and load.............. 30psi(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
Practically all 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:
²engine misfiring or vibrating severely
²sudden loss of power
²unusual engine noises
²fuel, oil or coolant leaks
²sudden change, outside the normal operating range, in
the engine operating temperature
²excessive smoke
²oil pressure drop
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ENGINE BLOCK HEATER (GAS ENGINES)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 a
grounded, three-wire extension cord.
The engine block heater cord, on gas engines, is routed
under the hood on the driver side of the vehicle. It has a
removable cap that is located on the driver side of the
Integrated Power Module.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110-115 volt electrical cord could cause
electrocution.
DIESEL EXHAUST BRAKE (ENGINE BRAKING) ±
IF EQUIPPED
The exhaust brake feature will only function when the
driver turns the exhaust brake switch to the on position.
Once the switch is in the on position and the vehicle is
moving faster than 5 MPH; the exhaust brake will
automatically operate when the driver removes pressure
from the accelerator pedal. Exhaust braking is most
effective when the engine RPM is higher. The automatic
transmission has been programmed to downshift more
aggressively when the exhaust brake is enabled to in-
crease brake performance.
270 STARTING AND OPERATING