Jeep Grand Cherokee 2013 Operating Information Manual page 229

Engine Idling – In Cold Weather
Avoid prolonged idling in ambient temperatures
below 0°F (-18°C). 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 com-
bustion 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.
Stopping The Engine
Before turning off your turbo diesel engine,
always allow the engine to return to normal idle
speed and run for several seconds. This as-
sures proper lubrication of the turbocharger.
This is particularly necessary after any period of
hard driving.
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 espe-
cially important for turbocharged, charge air
cooled engines.
AUTOMATIC TRANSMISSION
CAUTION!
Damage to the transmission may occur if the
following precautions are not observed:
• Shift into PARK only after the vehicle has
come to a complete stop.
• Shift into or out of REVERSE only after the
vehicle has come to a complete stop and
the engine is at idle speed.
• Do not shift between PARK, REVERSE,
NEUTRAL, or DRIVE when the engine is
above idle speed.
• Before shifting into any gear, make sure your
foot is firmly pressing the brake pedal.
NOTE:
You must press and hold the brake pedal
while shifting out of PARK.
WARNING!
• Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a ve-
hicle while the engine is running. Before
exiting a vehicle, always apply the parking
brake, shift the transmission into PARK,
turn the engine OFF, and remove the key
fob. When the ignition is in the OFF posi-
tion, the shift lever is locked in PARK,
securing the vehicle against unwanted
movement.
• It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher
than idle speed. If your foot is not firmly
pressing the brake pedal, the vehicle could
accelerate quickly forward or in reverse.
You could lose control of the vehicle and
hit someone or something. Only shift into
gear when the engine is idling normally
and your foot is firmly pressing the brake
pedal.
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