engine JEEP WRANGLER 2011 JK / 3.G Service Manual

STARTING PROCEDURES
Before starting your vehicle, adjust your seat, adjust both
inside and outside mirrors, and fasten your seat belts.
WARNING!
Never leave children in the vehicle alone. Leaving
unattended children in a vehicle is dangerous for a
number of reasons. The child or others could be
seriously or fatally injured. The child could operate
power windows, other controls or move the vehicle.
Manual Transmission – If Equipped
Apply the parking brake, place the shift lever in NEU-
TRAL, and press the clutch pedal before starting the
vehicle. This vehicle is equipped with a clutch interlock-
ing ignition system. It will not start unless the clutch
pedal is pressed to the floor.Four-Wheel Drive Models Only
In 4L mode, this vehicle will start regardless of whether
or not the clutch pedal is pressed to the floor. This feature
enhances off-road performance by allowing the vehicle to
start when in 4L without having to press the clutch pedal.
The “4WD Indicator Light” will illuminate when the
transfer case has been shifted into this mode.
Automatic Transmission – If Equipped
Start the vehicle with the shift lever in the PARK position
(vehicle can also be started in NEUTRAL). Apply the
brake before shifting to any driving range.
Normal Starting
NOTE:
Normal starting of either a cold or a warm
engine is obtained without pumping or pressing the
accelerator pedal.
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Turn the ignition switch to the START position and
release when the engine starts. If the engine fails to start
within 10 seconds, turn the ignition switch to the LOCK
position, wait 10 to 15 seconds, then repeat the “Normal
Starting” procedure.
Tip Start Feature – Automatic Transmission Only
Turn the ignition switch to the START position and
release it as soon as the starter engages. The starter motor
will continue to run, but will automatically disengage
itself when the engine is running. If the engine fails to
start, the starter will disengage automatically in 10 sec-
onds. If this occurs, turn the ignition switch to the LOCK
position, wait 10 to 15 seconds, then repeat the “Normal
Starting” procedure.
Extreme Cold Weather (Below –20°F Or –29°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.
If Engine Fails To Start
WARNING!
•Never pour fuel or other flammable liquids into
the throttle body air inlet opening in an attempt to
start the vehicle. This could result in a flash fire
causing serious personal injury.
•Do not attempt to push or tow your vehicle to get it
started. Vehicles equipped with an automatic trans-
mission cannot be started this way. Unburned fuel
could enter the catalytic converter and, once the
engine has started, ignite and damage the converter
and vehicle. If the vehicle has a discharged battery,
booster cables may be used to obtain a start from a
booster battery or the battery in another vehicle.
This type of start can be dangerous if done improp-
erly. Refer to “Jump Starting” in “What To Do In
Emergencies” for further information.
5
STARTING AND OPERATING 371

Without Tip Start – Manual Transmission Only
If the engine fails to start after you have followed the
“Normal Starting” or “Extreme Cold Weather” proce-
dures, it may be flooded. Push the accelerator pedal all
the way to the floor and hold it there while cranking the
engine. This should clear any excess fuel in case the
engine is flooded.
CAUTION!
To prevent damage to the starter, do not crank the
engine for more than 15 seconds at a time. Wait 10 to
15 seconds before trying again.
If the engine has been flooded, it may start to run, but not
have enough power to continue running when the key is
released. If this occurs, continue cranking with the accel-
erator pedal pushed all the way to the floor. Release the
accelerator pedal and the key once the engine is running
smoothly. If the engine shows no sign of starting after two 15–
second periods of cranking with the accelerator pedal
held to the floor, repeat the “Normal Starting” or “Ex-
treme Cold Weather” procedures.
With Tip Start – Automatic Transmission Only
If the engine fails to start after you have followed the
“Normal Starting” or “Extreme Cold Weather” proce-
dures, it may be flooded. To clear any excess fuel, push
the accelerator pedal all the way to the floor and hold it.
Then, turn the ignition switch to the START position and
release it as soon as the starter engages. The starter motor
will disengage automatically in 10 seconds. Once this
occurs, release the accelerator pedal, turn the ignition
switch to the LOCK position, wait 10 to 15 seconds, then
repeat the “Normal Starting” procedure.
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CAUTION!
To prevent damage to the starter, wait 10 to 15 sec-
onds before trying again.
After Starting
The idle speed will automatically decrease as the engine
warms up.
ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms the engine, 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 is found under the hood
bundled in front of the battery tray.
The engine block heater must be plugged in at least one
hour to have an adequate warming effect on the engine.
WARNING!
Remember to disconnect the engine block heater
cord before driving. Damage to the 110-115 Volt AC
electrical cord could cause electrocution.
MANUAL TRANSMISSION — IF EQUIPPED
WARNING!
You or others could be injured if you leave the
vehicle unattended without having the parking
brake fully applied. The parking brake should al-
ways be applied when the driver is not in the vehicle,
especially on an incline.5
STARTING AND OPERATING 373

You should always use 1st gear when starting from a
standing position if under heavy load or when pulling a
trailer.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for both
fuel economy and performance, it should be upshifted as
listed in recommended shift speed chart. Shift at the
vehicle speeds listed for acceleration. When heavily
loaded or pulling a trailer these recommended up-shift
speeds may not apply.
Manual Transmission Shift Speeds in MPH (KM/H)
En-
gine Speeds 1 to 2 2 to 3 3 to 4 4 to 5 5 to 6
3.8L Accel. 15 (24) 24 (39)34
(55) 47
(76) 56
(90)
Cruise 10 (16) 19 (31)27
(43) 37
(60) 41
(66)
Downshifting
Moving from a high gear down to a lower gear is
recommended to preserve brakes when driving down
steep hills. In addition, downshifting at the right time
provides better acceleration when you desire to resume
speed. Downshift progressively. Do not skip gears to
avoid overspeeding the engine and clutch.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip, and the vehicle could skid.
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STARTING AND OPERATING 375

CAUTION!
When descending a hill, be very careful to downshift
one gear at a time to prevent overspeeding the engine
which can cause valve damage, and/or clutch disc
damage, even if the clutch pedal is pressed.
Maximum Recommended Downshift Speeds
CAUTION!
Failure to follow the maximum recommended down-
shifting speeds may cause the engine to overspeed
and/or damage the clutch disc, even if the clutch
pedal is pressed.
Manual Transmission Downshift Speeds in MPH(KM/H)
Gear
Selec-
tion 6to5 5to4 4to3 3to2 2to1
Maxi-
mum
Speed 80 (129) 70 (113) 50 (81) 30 (48) 15 (24)
Reverse Shifting
To shift into REVERSE, bring the vehicle to a complete
stop. Press the clutch and pause briefly to allow the gear
train to stop rotating. Beginning from the NEUTRAL
position, move the shift lever in one quick, smooth
motion straight across and into the REVERSE area (the
driver will feel a firm “click” as the shifter passes the
“knock-over”). Complete the shift by pulling the shift
lever into REVERSE.
376 STARTING AND OPERATING

The “knock-over” prevents the driver from accidentally
entering the REVERSE shift area and warns the driver
that they are about to shift the transmission into RE-
VERSE. Due to this feature, a slow shift to REVERSE can
be perceived as a high shift effort.
AUTOMATIC TRANSMISSION — IF EQUIPPED
CAUTION!
Damage to the transmission may occur if the follow-
ing 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.(Continued)
CAUTION! (Continued)
•Do not shift from REVERSE, PARK, or NEUTRAL
into any forward gear when the engine is above
idle speed.
•Before shifting into any gear, make sure your foot
is firmly on the brake pedal.
WARNING!
It is dangerous to move the shift lever out of PARK or
NEUTRAL if the engine speed is higher than idle
speed. If your foot is not firmly on 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 when your foot is
firmly on the brake pedal.5
STARTING AND OPERATING 377

Key Ignition Park Interlock
This vehicle is equipped with a Key Ignition Park Inter-
lock which requires the shift lever to be placed in PARK
prior to rotating the key to the LOCK position. The key
can only be removed from the ignition when the ignition
is in the LOCK position. Once the key is removed, the
shift lever is locked in PARK.
Brake/Transmission Interlock System
This vehicle is equipped with a Brake Transmission Shift
Interlock System (BTSI) that holds the shift lever in the
PARK position when the ignition switch is in the ON or
START position and the brake pedal is not pressed. To
move the shift lever out of the PARK position, the
ignition switch must be turned to the ON or START
position (engine running or not) and the brake pedal
must be pressed.
Automatic Transmission With Overdrive
Shifting from DRIVE to PARK or REVERSE (or from P or
R to D) should be done only after the accelerator pedal is
released and the vehicle is stopped. Be sure to keep your
foot on the brake when moving the shift lever between
these gears.
Shift Lever
378 STARTING AND OPERATING

Gear Ranges
NOTE:Under extreme cold temperatures (-10°F (-23°C)
and when in DRIVE, transmission operation may be
briefly limited to only second gear operation. Normal
operation will resume once the transmission temperature
has risen to a suitable level.
DO NOT race the engine when shifting from PARK or
NEUTRAL position into another gear range.
PARK
This range supplements the parking brake by locking the
transmission. The engine can be started in this range.
Never use PARK while the vehicle is in motion. Apply
the parking brake when leaving the vehicle in this range.
Always apply the parking brake first, then place the shift
lever in the PARK position.
WARNING!
•Never use the PARK position as a substitute for
the parking brake. Always apply the parking
brake fully when parked to guard against vehicle
movement and possible injury or damage.
•It is dangerous to move the shift lever out of PARK
or NEUTRAL if the engine speed is higher than
the idle speed. If your foot is not firmly on 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
when your right foot is firmly on the brake pedal.
REVERSE
This range is for moving the vehicle backward. Use only
after the vehicle has come to a complete stop.
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STARTING AND OPERATING 379

NEUTRAL
This range is used when vehicle is standing for pro-
longed periods with engine running. Engine may be
started in this range. Set the parking brake and shift the
transmission into PARK if you must leave the vehicle.
NOTE:Towing, coasting, or driving the vehicle for any
other reason with the shift lever in NEUTRAL can result
in severe transmission damage. Refer to “Recreational
Towing” in “Starting and Operating” and “Towing a
Disabled Vehicle” in “What To Do In Emergencies” for
further information.
OVERDRIVE
This range is used for most city and highway driving.
The transmission contains an electronically-controlled
fourth gear Overdrive, and will automatically shift from
DRIVE to OVERDRIVE if the following conditions are
present:
•The shift lever is in DRIVE.
•The O/D OFF switch has not been activated.
•Vehicle speed is above approximately 30 mph
(48 km/h).
When frequent transmission shifting occurs while using
Overdrive, such as when operating the vehicle under
heavy load conditions (for example, in hilly terrain,
strong head winds, or trailer towing), turning off over-
drive will improve performance and extend transmission
life by reducing excessive shifting and heat buildup.
380 STARTING AND OPERATING