engine JEEP WRANGLER 2006 Owner's Guide

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)

Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
CAUTION!
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.
WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing that can burn.

Fuel Filter
A plugged fuel filter can cause hard starting or limit the
speed at which a vehicle can be driven. Should an
excessive amount of dirt accumulate in the fuel tank,
frequent replacement of the fuel filter which is mounted
in the fuel tank may be necessary.
Engine Air Cleaner Filter
Under normal driving conditions, replace the air filter at
the intervals shown on “Maintenance Schedule A.” If,
however, you drive the vehicle frequently under dusty or
severe conditions, the filter element should be inspected
periodically and replaced if necessary at the intervals
shown on “Maintenance Schedule B.”
WARNING!
The air cleaner can provide protection in the case of
engine backfire. Do not remove the air cleaner
unless it is necessary for repair or maintenance.
Make sure that no one is near the engine compart-
ment before starting the vehicle with the air cleaner
removed. Failure to do so can result in serious
personal injury.

Fluid level should be checked on a level surface with
the engine off to prevent injury from moving parts,
and to insure accurate fluid level reading. Do not
overfill. Use only the manufacturer’s recommended
fluid.
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have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seep
into the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
Cooling System
WARNING!
You or others can be badly burned by hot antifreeze/
coolant or steam from your radiator. If you see or
hear steam coming from under the hood, don’t open
the hood until the radiator has had time to cool.
Never try to open a cooling system pressure cap
when the radiator or coolant bottle is hot.
Engine Coolant Checks
Check antifreeze/coolant protection every 12 months
(before the onset of freezing weather, where applicable).
If antifreeze/coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
antifreeze/coolant. Check the front of the A/C condenser
(if equipped) or radiator for any accumulation of bugs,
leaves, etc. If dirty, clean by gently spraying water from a
garden hose vertically down the face of the A/C con-
denser (if equipped) or the back of the radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of the connection at
the coolant recovery bottle and radiator. Inspect the
entire system for leaks.
284 MAINTAINING YOUR VEHICLE

Adding Engine Coolant
Your vehicle has been built with an improved antifreeze/
coolant that allows extended maintenance intervals. This
antifreeze/coolant can be used up to 5 Years or 100,000
miles before replacement. To prevent reducing this ex-
tended maintenance period, it is important that you use
the same antifreeze/coolant throughout the life of your
vehicle. Please review these recommendations for using
Hybrid Organic Additive Technology (HOAT)
antifreeze/coolant.
When adding antifreeze/coolant, a minimum solution of
50% recommended Mopar Antifreeze/ Coolant 5 Year/
100,000 Mile Formula HOAT (Hybrid Organic Additive
Technology), or equivalent, in water should be used. Use
higher concentrations (not to exceed 70%) if temperatures
below -34°F (-37°C) are anticipated.
286 MAINTAINING YOUR VEHICLE

The warning words DO NOT OPEN HOT on the
cooling system pressure cap are a safety precaution.
Never add antifreeze/coolant when the engine is
overheated. Do not loosen or remove the cap to cool
an overheated engine. Heat causes pressure to build
up in the cooling system. To prevent scalding or
injury, do not remove the pressure cap while the
system is hot or under pressure.
Disposal of Used Engine Coolant
Used ethylene glycol based antifreeze/coolant is a regu-
lated substance requiring proper disposal. Check with
your local authorities to determine the disposal rules for
your community. To prevent ingestion by animals or
MAINTAINING YOUR VEHICLE 287
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are present. Components should be replaced immedi-
ately if there is any evidence of degradation that could
cause failure.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the appropriate “Maintenance Schedule” in
Section 8 for suggested service intervals.
WARNING!
Riding the brakes can lead to brake failure and
possibly an accident. Driving with your foot resting
or riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You wouldn’t have your full
braking capacity in an emergency.
Brake and Power Steering System Hoses
When servicing the vehicle for scheduled maintenance,
inspect surface of hoses for evidence of heat and me-
chanical damage. Hard and brittle rubber, cracking, tears,
cuts, abrasion, and excessive swelling suggest deteriora-
tion of the rubber. Particular attention should be made to
examining those hose surfaces nearest to high heat
sources, such as the exhaust manifold.
Inspect all hose clamps and couplings to make sure they
are secure and no leaks are present.
NOTE: Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.
290 MAINTAINING YOUR VEHICLE

Using a transmission fluid other than the manufac-
turer’s recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
shudder. Using a transmission fluid other than the
manufacturer’s recommended fluid will result in
more frequent fluid and filter changes. Refer to
Fluids, Lubricants, and Genuine Parts for correct
fluid type.
Fluid Level Check — 42RLE
This fluid level should be checked when the engine is
fully warmed up and the fluid in the transmission is
heated to its normal operating temperature. Operation of
the transmission with an improper fluid level will greatly
reduce the life of the transmission and of the fluid. To check the automatic transmission fluid level properly,
the following procedure must be used:
1. The vehicle must be on level ground.
2. The engine should be running at curb idle speed for a
minimum of 60 seconds.
3. Fully apply parking brake.
4. Apply the brakes and shift the transmission momen-
tarily into each gear position ending in P (Park).
5. The fluid
MUSTbe checked with the transmission in
P (Park) to be sure that the fluid level is accurate.
6. Wipe the dipstick clean and reinsert until seated.
Remove dipstick and note reading.
At normal operating temperature (approximately 180° F
(82° C), the fluid level is correct if it is in the HOT region
MAINTAINING YOUR VEHICLE 293
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Cavity Fuse/Color Description
29 Relay ASD
30 Relay A/C Clutch
31 Relay Transmission
32 Relay Starter
33 Relay ABS
34 Open
35 Relay Fog Lamp
36 Relay Horn
37 Relay Fuel Pump
38 Relay HBL (Rear Window Defroster)
39 Relay Front Differential Locker (Ru- bicon) or High Speed Fan
(2.4L Engines)
40 Relay Rear Differential Locker (Ru- bicon) or Low Speed Fan
(2.4L Engines)
308 MAINTAINING YOUR VEHICLE