2015 JEEP GRAND CHEROKEE oil temperature

ENGINE BREAK-IN RECOMMENDATIONS
The diesel engine does not require a break-in period due
to its construction. Normal operation is allowed, provid-
ing the following recommendations are followed:
•Warm up the engine before placing it under load.
•Do not operate the engine at idle for prolonged
periods.
•Use the appropriate transmission gear to prevent
engine lugging.
•Observe vehicle oil pressure and temperature indica-
tors.
•Check the coolant and oil levels frequently.
•Vary throttle position at highway speeds when carry-
ing or towing significant weight.NOTE:Light duty operation such as light trailer towing
or no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy and
power may be seen at this time.
The engine oil installed in the engine at the factory is a
high-quality energy conserving type lubricant. Oil
changes should be consistent with anticipated climate
conditions under which vehicle operations will occur.
The recommended viscosity and quality grades are
shown under “Fluids, Lubricants and Genuine Parts”,
under “Maintaining Your Vehicle” in this manual. NON-
DETERGENT OR STRAIGHT MINERAL OILS MUST
NEVER BE USED.
10 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

12. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating properly.
The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
NOTE:Temperature readings in the orange range of the
gauge are acceptable under some high load condition. If
the gauge points to the H orEngine Temperature Hot
DID message appears a light and a single chime will
require driver correction.CAUTION!
Driving with a hot engine cooling system could
damage your vehicle. If the temperature gauge reads
“H” pull over and stop the vehicle. Idle the vehicle
with the air conditioner turned off until the pointer
drops back into the normal range. If the pointer
remains on the “H” and you hear continuous chimes,
turn the engine off immediately and call an autho-
rized dealer for service.
WARNING!
A hot engine cooling system is dangerous. You or
others could be badly burned by steam or boiling
coolant. You may want to call an authorized dealer
for service if your vehicle overheats. If you decide to
look under the hood yourself, see “Maintaining Your
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16 UNDERSTANDING YOUR INSTRUMENT PANEL

NORMAL OPERATION
Observe the following when the diesel engine is operat-
ing.
•All message center lights are off.
•Malfunction Indicator Light (MIL) is off.
•Engine Oil Pressure telltale is not illuminated.
•Voltmeter operation:
The voltmeter may show a gauge fluctuation at various
engine temperatures. This is caused by the glow plug
heating system. The number of cycles and the length of
the cycling operation is controlled by the engine control
module. Glow plug heater operation can run for several
minutes, once the heater operation is complete the volt-
meter needle will stabilize.
Cold Weather Precautions
Operation in ambient temperature below 32°F (0°C) may
require special considerations. The following charts sug-
gest these options:
Fuel Operating Range
NOTE:Use “Ultra Low Sulfur Diesel Fuels”ONLY.
*No. 1 Ultra Low Sulfur Diesel Fuel should only be used
where extended arctic conditions (-10°F/-23°C) exist.
Fuel Operating Range Chart
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STARTING AND OPERATING 41

NOTE:
•Use of Climatized Ultra Low Sulfur Diesel Fuel or
Number 1 Ultra Low Sulfur Diesel Fuel results in a
noticeable decrease in fuel economy.
•Climatized Ultra Low Sulfur Diesel Fuel is a blend of
Number 2 Ultra Low Sulfur and Number 1 Ultra Low
Sulfur Diesel Fuels which reduces the temperature at
which wax crystals form in fuel.
•The fuel grade should be clearly marked on the pump
at the fuel station.
•The engine requires the use of“Ultra Low Sulfur
Diesel Fuel”. Use of incorrect fuel could result in
engine and exhaust system damage. Refer to “Fuel
Requirements” in “Starting And Operating” for fur-
ther information.•Commercially available fuel additives are not neces-
sary for the proper operation of your diesel engine.
However, if seasonably adjusted fuel is not available
and you are operating below 20°F (-6°C), MOPAR
Premium Diesel Fuel Treatment (or equivalent) may be
beneficial to avoid fuel gelling.
Engine Oil Usage
Refer to “Maintenance Procedures” in “Maintaining Your
Vehicle” for the correct engine oil viscosity.
Engine Warm-Up
Avoid full throttle operation when the engine is cold.
When starting a cold engine, bring the engine up to
operating speed slowly to allow the oil pressure to
stabilize as the engine warms up.
If temperatures are below 32°F (0°C), operate the engine
at moderate speeds for five minutes before full loads are
applied.
42 STARTING AND OPERATING

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
varnish to form on piston rings, cylinder head valves,
and injector nozzles. Also, the unburned fuel can enter
the crankcase, diluting the oil and causing rapid wear to
the engine.
Stopping The Engine
After full load operation, idle the engine for a few
minutes before shutting it down. This idle period will
allow the lubricating oil and coolant to carry excess heat
away from the turbocharger.
NOTE:Refer to the following chart for proper engine
shutdown.
Driving Condition LoadTurbocharger
TemperatureIdle Time (min.) Before
Engine Shutdown
Stop and Go Empty Cool None
Stop and Go Medium 0.5
Highway Speeds Medium Warm 1.0
City Traffic Maximum GCWR 1.5
Highway Speeds Maximum GCWR 2.0
Uphill Grade Maximum GCWR Hot 2.5
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STARTING AND OPERATING 43

NOTE:Under certain conditions the engine fan will run
after the engine is turned off. These conditions are under
high load and high temperature conditions.
Cooling System Tips — Automatic Transmission
To reduce the potential for engine and transmission
overheating 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.
NOTE:If the coolant temperature is too high the A/C
will automatically turn off.
Do Not Operate The Engine With Low Oil
Pressure
If the low oil pressure warning light turns on while
driving, stop the vehicle and shut down the engine as
soon as possible. A chime will sound when the light turns
on.
NOTE:Do not operate the vehicle until the cause is
corrected. This light does not show how much oil is in the
engine. The engine oil level must be checked under the
hood.
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.
44 STARTING AND OPERATING

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.
Its use is recommended for environments that routinely
fall below -10°F (-23°C). It should be used when the
vehicle has not been running for long periods of time and
should be plugged in two hours prior to start. Its use is
required for cold starts with temperatures under -20°F
(-28°C).
To ensure reliable starting at these temperatures, use of
an externally powered electric engine block heater (avail-
able from your authorized dealer) is recommended.
4
STARTING AND OPERATING 45

which is recommended for all operating temperatures.
This engine oil improves low temperature starting and
vehicle fuel economy.
Materials Added To Engine Oil
The manufacturer strongly recommends against the ad-
dition of any additives (other than leak detection dyes) to
the engine oil. Engine oil is an engineered product and its
performance may be impaired by supplemental addi-
tives.
Engine Oil Filter
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information. The
engine oil filter should be changed at every engine oil
change.
Disposing Of Used Engine Oil And Oil Filters
Care should be taken in disposing of used engine oil and
oil filters from your vehicle. Used oil and oil filters,indiscriminately discarded, can present a problem to the
environment. Contact your authorized dealer, service
station or governmental agency for advice on how and
where used oil and oil filters can be safely discarded in
your area.
Engine Air Cleaner Filter
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
CAUTION!
All air entering the engine intake must be filtered.
The abrasive particles in unfiltered air will cause
rapid wear to engine components.
78 MAINTAINING YOUR VEHICLE