engine coolant DODGE RAM 4500 CHASSIS CAB 2008 3.G User Guide

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
STARTING AND OPERATING 267
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
STARTING AND OPERATING 269
5

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

NOTE:For optimum braking power it is recommended
to use the Exhaust Brake while in Tow/Haul Mode.
The purpose of the exhaust brake (engine braking) fea-
ture is to supply negative (braking) torque to 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 spar-
ing the mechanical brakes of the vehicle.Benefits of the exhaust brake are:
²vehicle driving control
²reduced brake fade
²longer brake life
²faster cab warm-up.
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 moving less than 5
MPH, the exhaust brake switch must be in the on
position, and the coolant temperature must below 180 F
and ambient temperature below 60 F.
272 STARTING AND OPERATING

ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth speed (Overdrive).
The transmission will automatically shift from Drive to
Overdrive if the following conditions are present:
²the transmission selector is in Drive;
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.
276 STARTING AND OPERATING

NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 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 into Overdrive when cold. This is normal.
Pressing the ªTOW/HAULº button, when the transmis-
sion is sufficiently warm, will demonstrate that the
transmission is able to shift into and out of overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission 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 of shifting from Park into
any other gear position.Automatic Transmission (6 Speed AS68RC) Ð If
Equipped
The gear shift selector display, located in the instrument
panel cluster, indicates the transmission gear range (the
selector is illuminated for night driving). The selector
lever is mounted on the right side of the steering column.
You must depress the brake pedal, to pull the selector
lever out of park (P) position (Brake Interlock System). To
drive, move the selector lever from Park or Neutral to the
desired drive position. Pull the selector lever toward you
when shifting into Reverse, Second, First or Park, or
when shifting out of Park.
Gear Ranges
DO NOT race the engine when shifting from Park or
Neutral position into another gear range.
STARTING AND OPERATING 279
5

ª2º Second
Use this position for driving on more severe conditions
and lower speeds than ª3º third. To prevent excessive
engine speed do not exceed 25 mph (40 km/h) in this
range.
ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 12 mph (19 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 12 mph (19 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled 5th and 6th (if equipped) speed(Overdrive). The transmission will automatically shift
from Drive to Overdrive if the following conditions are
present:
²the transmission selector is in Drive;
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 38 mph (61
km/h) for 5th gear and 55 mph (89 km/h) for 6th gear;
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission shift schedule initially re-
stricts transmission operation in forward gear ranges to
3rd gear until the transmission fluid temperature rises to
282 STARTING AND OPERATING