engine JEEP WRANGLER 2007 JK / 3.G Workshop Manual

Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your dealer for service assistance.
•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of theseproducts contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
324 STARTING AND OPERATING

garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Keep the swing gate closed when driving your vehicle
to prevent carbon monoxide and other poisonous
exhaust gases from entering the vehicle.
ADDING FUEL
Fuel Filler Cap (Gas Cap)
The gas cap is located on the driver’s side of the vehicle.
If the gas cap is lost or damaged, be sure the replacement
cap is for use with this vehicle.
Fuel Filler Cap
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CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel cap
(gas cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly fitting after-
market cap can cause the MIL (Malfunction Indicator
Light) to illuminate, due to fuel vapors escaping from
the system.
CAUTION!
A poorly fitting gas cap may cause the Malfunction
Indicator Light to turn on.
CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE:When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
WARNING!
•Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
•Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and will cause the malfunction indicator
light to turn on.
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NOTE:Tighten the gas cap about 1/4 turn until you
hear one click. This is an indication that cap is properly
tightened.
If the gas cap is not tighten properly, the Malfunction
Indicator Light will come on. Be sure the gas cap is
tightened every time the vehicle is refueled.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel tank
filler cap (gas cap). A poorly fitting cap could let
impurities into the fuel system.
WARNING!
•Never add fuel when the engine is running.
•Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
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Trailer Towing Weights (Maximum Trailer Weight Ratings)
The following chart provides the maximum trailer weight ratings towable for your given drivetrain.
Engine/
Transmis-
sionAxle Model GCWR (Gross
Combined Wt.
Rating)Frontal Area Max. GTW (Gross
Trailer Wt.)Max. Tongue Wt.
(See Note 1)
3.8L/
Manual3.21 2 Door X Model
(4WD)4,932 lbs (2 237 kg) 25 sq. ft. (2.32
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
3.8L/
Manual4.10 2 Door X Model
(4WD)5,932 lbs (2 691 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
3.8L/
Automatic4.10 2 Door X Model
(4WD)5,955 lbs (2 701 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
3.8L/
Manual3.21 2 Door Sahara
Model (4WD)5,102 lbs (2 314 kg) 25 sq. ft. (2.32
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
3.8L/
Manual4.10 2 Door Sahara
Model (4WD)6,102 lbs (2 768 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
3.8L/
Automatic4.10 2 Door Sahara
Model (4WD)6,126 lbs (2 779 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
3.8L/
Manual4.10 2 Door Rubicon
Model (4WD)6,219 lbs (2 821 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
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Engine/
Transmis-
sionAxle Model GCWR (Gross
Combined Wt.
Rating)Frontal Area Max. GTW (Gross
Trailer Wt.)Max. Tongue Wt.
(See Note 1)
3.8L/
Automatic4.10 2 Door Rubicon
Model (4WD)6,243 lbs (2 832 kg) 25 sq. ft. (2.32
square meters)2,000 lbs (907 kg) 200 lbs (91 kg)
3.8L/
Manual3.21 4 Door X Model
(2WD)5,126 lbs (2 325 kg) 32 sq. ft. (2.97
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
3.8L/
Manual4.10 4 Door X Model
(2WD)7,626 lbs (3 459 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Automatic4.10 4 Door X Model
(2WD)7,649 lbs (3 469 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Manual3.21 4 Door Sahara
Model (2WD)5,289 lbs (2 399 kg) 32 sq. ft. (2.97
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
3.8L/
Manual4.10 4 Door Sahara
Model (2WD)7,789 lbs (3 533 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Automatic4.10 4 Door Sahara
Model (2WD)7,812 lbs (3 543 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Manual3.21 4 Door X Model
(4WD)5,330 lbs (2 418 kg) 32 sq. ft. (2.97
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
336 STARTING AND OPERATING

Engine/
Transmis-
sionAxle Model GCWR (Gross
Combined Wt.
Rating)Frontal Area Max. GTW (Gross
Trailer Wt.)Max. Tongue Wt.
(See Note 1)
3.8L/
Manual4.10 4 Door X Model
(4WD)7,830 lbs (3 552 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Automatic4.10 4 Door X Model
(4WD)7,853 lbs (3 562 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Manual3.21 4 Door Sahara
Model (4WD)5,497 lbs (2 493 kg) 32 sq. ft. (2.97
square meters)1,000 lbs (453 kg) 100 lbs (45 kg)
3.8L/
Manual4.10 4 Door Sahara
Model (4WD)7,997 lbs (3 627 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Automatic4.10 4 Door Sahara
Model (4WD)8,020 lbs (3 638 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Manual4.10 4 Door Rubicon
Model (4WD)8,059 lbs (3 655 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
3.8L/
Automatic4.10 4 Door Rubicon
Model (4WD)8,083 lbs (3 666 kg) 32 sq. ft. (2.97
square meters)3,500 lbs (1 587 kg) 350 lbs (159 kg)
Refer to local laws for maximum trailer towing speeds.
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WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have an accident.
•When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
frame or hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
•Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle automatic transmission in
P (Park). With a manual transmission, shift the trans-
mission into 1st gear. And with four-wheel-drive ve-
hicles, make sure the transfer case is not in N (Neu-
tral). Always, block orchockthe trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
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Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Towing Tips — Automatic Transmission
The “D” range can be selected when towing. However, if
frequent shifting occurs while in this range, the “3” range
should be selected.
NOTE:Using the “3” range while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
7- Pin Connector
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The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See “Schedule B” in
section 8 of this manual for transmission fluid change
intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips — O/D Off (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the “O/D OFF” feature OFF when driving in
hilly areas or shift the transmission to Drive position 2 on
more severe grades. Refer to “Transmission Shifting” in
this section.
Towing Tips — Electronic Speed Control (If
Equipped)

Don’t use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
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