coolant temperature Ram 1500 2015 Diesel Supplement

NOTE:Excessive white smoke and poor engine perfor-
mance will result if manifold heaters are not recycled.
2. Heat generated by the manifold heaters dissipates rapidly in a cold engine. If more than two minutes
pass between the time the “Wait To Start” telltale turns
off and the engine is started, recycle the manifold
heaters by turning the ignition switch to the OFF
position for at least five seconds and then back ON.
3. If the vehicle is driven and vehicle speed exceeds 19 mph (31 km/h) before the manifold heater post-
heat (after start) cycle is complete, the manifold heat-
ers will shut off.
4. If the engine is started before the “Wait To Start” telltale turns off, the preheat cycle will turn off.
5. If the engine is cranked for more than 10 seconds, the post-heat cycle will turn off. NOTE:
•
Engine idle speed will automatically increase to 1,000
RPM and engage the Variable Geometry Turbocharger
at low coolant temperatures to improve engine warm-
up.
• 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. If your engine has run out of fuel, refer to
“Maintenance Procedures/Priming If The Engine Has
Run Out Of Fuel” in “Maintaining Your Vehicle” for
further information.
• If the engine stalls, or if the ignition switch is left ON
for more than two minutes after the “Wait To Start”
telltale goes out, reset the grid heaters by turning the
ignition switch to the OFF position for at least five
seconds and then back ON. Repeat steps 1 through 5 of
“Starting Procedure – Engine Manifold Air Tempera-
ture Below 66°F (19°C).”
216 STARTING AND OPERATING

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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STARTING AND OPERATING 221

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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STARTING AND OPERATING 225

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
226 STARTING AND OPERATING

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.
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
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STARTING AND OPERATING 227

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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STARTING AND OPERATING 229

Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0°F (-18°). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 Volt AC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized MOPAR® dealer.
Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
you see or hear steam coming from under the hood,
do not open the hood until the radiator has had time
to cool. Never try to open a cooling system pressure
cap when the radiator is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh coolant. Check the front of
the A/C condenser (if equipped) or radiator for any
accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the A/C condenser (if equipped) or the back of the
radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts and tightness of the connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
298 MAINTAINING YOUR VEHICLE

CAUTION!(Continued)
•Do not use water alone or alcohol-based engine
coolant (antifreeze) products. Do not use additional
rust inhibitors or antirust products, as they may not
be compatible with the radiator engine coolant and
may plug the radiator.
• This vehicle has not been designed for use with
propylene glycol-based engine coolant (antifreeze).
Use of propylene glycol-based engine coolant (an-
tifreeze) is not recommended.
Adding Coolant
Your vehicle has been built with an improved engine
coolant (OAT coolant conforming to MS.90032) that al-
lows extended maintenance intervals. This engine cool-
ant (antifreeze) can be used up to ten years or 150,000
miles (240,000 km) before replacement. To prevent reduc-
ing this extended maintenance period, it is important that you use the same engine coolant (OAT coolant conform-
ing to MS.90032) throughout the life of your vehicle.
Please review these recommendations for using Organic
Additive Technology (OAT) engine coolant (antifreeze)
that meets the requirements of FCA Material Standard
MS.90032. When adding engine coolant (antifreeze):
•
We recommend using MOPAR® Antifreeze/Coolant
10 Year/150,000 Mile Formula OAT (Organic Additive
Technology) that meets the requirements of FCA Ma-
terial Standard MS.90032.
• Mix a minimum solution of 50% OAT engine coolant
that meets the requirements of FCA Material Standard
MS.90032 and distilled water. Use higher concentra-
tions (not to exceed 70%) if temperatures below 34° F
(37° C) are anticipated.
• Use only high purity water such as distilled or deion-
ized water when mixing the water/engine coolant
300 MAINTAINING YOUR VEHICLE

(antifreeze) solution. The use of lower quality water
will reduce the amount of corrosion protection in the
engine cooling system.
Please note that it is the owner’s responsibility to main-
tain the proper level of protection against freezing ac-
cording to the temperatures occurring in the area where
the vehicle is operated.
NOTE:
• Some vehicles require special tools to add coolant
properly. Failure to fill these systems properly could
lead to severe internal engine damage. If any coolant is
needed to be added to the system please contact your
local authorized dealer. •
Mixing engine coolant (antifreeze) types is not recom-
mended and can result in cooling system damage. If
HOAT and OAT coolant are mixed in an emergency,
have a authorized dealer drain, flush, and refill with
OAT coolant (conforming to MS.90032) as soon as
possible.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that the engine coolant
(antifreeze) will return to the radiator from the coolant
expansion bottle.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
6
MAINTAINING YOUR VEHICLE 301

•Check the coolant freeze point in the radiator and in
the coolant expansion bottle. If engine coolant (anti-
freeze) needs to be added, the contents of the coolant
expansion bottle must also be protected against freez-
ing.
• If frequent engine coolant (antifreeze) additions are
required, the cooling system should be pressure tested
for leaks.
• Maintain engine coolant (antifreeze) concentration at a
minimum of 50% OAT coolant (conforming to
MS.90032) and distilled water for proper corrosion
protection of your engine which contains aluminum
components.
• Make sure that the coolant expansion bottle overflow
hoses are not kinked or obstructed.
• Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean. •
Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory engine coolant (antifreeze)
performance, poor gas mileage, and increased emis-
sions.
Charge Air Cooler — Inter-Cooler
The charge air cooler is positioned below the radiator and
the air conditioner condenser. Air enters the engine
through the air cleaner and passes through the turbo-
charger, where it is pressurized. This pressurized air
rapidly reaches high temperature. The air is then directed
through a hose to the charge air cooler and through
another hose to the intake manifold of the engine. The air
entering the engine has been cooled by about 50° to 100°F
(10° to 38°C). This cooling process enables more efficient
burning of fuel resulting in fewer emissions.
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MAINTAINING YOUR VEHICLE 303