engine JEEP WRANGLER 1999 Service Manual

Unintended movement of a vehicle could injure
those in and near the vehicle. As with all vehicles,
you should never exit a vehicle while the engine is
running. Before exiting a vehicle, you should always
shift the vehicle into P (Park), remove the key from
the ignition, and apply the parking brake. Once the
key is removed from the ignition, the transmission
shift lever is locked in the P (Park) position, securing
the vehicle against unwanted movement. Further-
more, you should never leave children unattended
inside a vehicle.

Failure to engage a position completely can cause
transfer case damage or loss of power and vehicle
control. You could have an injury accident. Do not
drive the vehicle unless the transfer case is fully
engaged.
On vehicles equipped with a limited-slip differen-
tial, never run the engine with one rear wheel off the
ground. The vehicle may drive through the rear
wheel remaining on the ground and cause you to
lose control of your vehicle.

To use your brakes and decelerate more safely, follow these tips:
•Do not “ride” the brakes by resting your foot on the pedal. This
could overheat the brakes and result in unpredictable braking
action, longer stopping distances, or brake damage.
•When descending mountains or hills, repeated braking can cause
brake fade with loss of braking control. Avoid repeated heavy
braking by downshifting the transmission whenever possible.
•Do not downshift on icy or slippery roads, because engine braking
may cause skidding and loss of control.
•Engines may idle at higher speeds during warm-up, which could
cause rear wheels to spin and result in loss of vehicle control. Be
especially careful while driving on slippery roads, in close-quarter
maneuvering, parking or stopping. Remember, always engage
4-wheel drive when driving on slippery roads.
•Do not drive too fast for road conditions, especially when roads are wet
or slushy. A wedge of water can build up between the tire tread and the
road. This hydroplaning action can cause loss of traction, braking
ability, and control. Under such conditions, engage 4-wheel drive.
•After going through deep water or a car wash, brakes may become
wet, resulting in poor performance and unpredictable braking
action. Dry the brakes by gentle, intermittent pedal action while
driving at very slow speeds.
WARNING!
The weight and position of cargo and passengers can change
the vehicle center of gravity and vehicle handling. To avoid
loss of control resulting in personal injury, follow these
guidelines:
•Always place cargo evenly on the cargo floor, and locate
heavier objects as low and as far forward as possible.
•Place as much cargo as possible in front of the rear axle. Too
much weight or improperly placed weight over or behind
the rear axle can cause the rear of the vehicle to sway.
•Do not pile luggage or cargo higher than the top of the
seatback. This could impair visibility or become a danger-
ous projectile in a sudden stop or collision.
•The rear cargo space is intended for load carrying purposes
only, not for passengers, who should sit in seats and use
seat belts.
•On hardtop models, do not drive with the lift glass up. On
fabric top models, do not drive with the rear window
curtain up unless the side curtains are also open. This will
prevent dangerous exhaust fumes from entering the ve-
hicle.

To help avoid personal injury, follow these tips:
•Never reach through the steering wheel to operate
steering column controls. Injury to your hands or
loss of vehicle control may result.
•If the engine stalls or power assist fails due to a
malfunction, vehicle steering and braking will
require greater effort.Significant over or under-inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.

If the engine stalls or you lose headway or cannot
make it to the top of a steep hill or grade, never
attempt to turn around. To do so may result in
tipping and rolling the vehicle. Always back care-
fully straight down a hill in R (Reverse) gear. Never
back down a hill in N (Neutral) using only the brake.
Remember, never drive diagonally across a hill-always
drive straight up or down.
If the wheels start to slip as you approach the crest of a
hill, ease off the accelerator and maintain headway byturning the front wheels slowly left and right. This may
provide a fresh “bite” into the surface and will usually
provide traction to complete the climb.
Traction Downhill
Shift the transmission into a low gear and the transfer
case to 4L (Low) range. Let the vehicle go slowly down
the hill with all four wheels turning against engine
compression drag. This will permit you to control the
vehicle speed and direction.
When descending mountains or hills, repeated braking
can cause brake fade with loss of braking control. Avoid
repeated heavy braking by downshifting the transmis-
sion whenever possible.
STARTING AND OPERATING 205

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.
TRAILER TOWING
In this section you will find information on limits to the
type of towing you can reasonably do with your vehicle.
Before towing a trailer, carefully review this information
to tow your load as efficiently and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.Perform maintenance services as prescribed in the
“Maintenance Schedules” section. When your vehicle is
used for trailer towing, never exceed the gross axle
weight rating (GAWR) by the addition of:
•The tongue weight of the trailer.
•The weight of any other type of cargo or equipment
put in or on your vehicle.
Remember that everything put in or on the trailer adds to
the load on your vehicle.
The “D” Overdrive range can be selected when towing.
However, if frequent shifting occurs move the shift lever
to the next lower position to eliminate excessive auto-
matic transmission shifting. This action will also reduce
the possibility of transmission overheating and provide
better engine braking. Refer to “Transmission Shifting” in
this section for additional information.
STARTING AND OPERATING 229

Damage to the transmission may occur if the trans-
mission is shifted into P (Park) with the transfer case
in N (Neutral) and the engine running. With the
transfer case in N (Neutral) ensure that the engine is
off prior to shifting the transmission into P (Park)
(refer to steps7 – 8 above).

Driving with a hot 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 for service.

Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
•Day or night temperatures are below 32°F (0°C)
•Stop and go driving
•Extensive engine idling
•Driving in dusty conditions
•Short trip driving of less than 10 miles (16.2 km)

Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.