check engine JEEP LIBERTY 2006 User Guide

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 Hybrid Organic Additive Technology (HOAT)
antifreeze/coolant is a regulated substance requiring
proper disposal. Check with your local authorities to
determine the disposal rules for your community. To prevent ingestion by animals or children, do not store
HOAT antifreeze/coolant in open containers, or allow it
to remain in puddles on the ground. If ingested by a
child, contact a physician immediately. Clean up ground
spills immediately.
Engine Coolant Level
The coolant recovery bottle provides a quick visual
method for determining that the antifreeze/coolant level
is adequate. With the engine idling, and warm to normal
operating temperature, the level of the antifreeze/coolant
should be between the ranges indicated on the bottle.
The radiator normally remains completely full, so there is
no need to remove the radiator cap unless checking for
antifreeze/coolant freeze point or replacing coolant. Ad-
vise your service attendant of this. As long as the engine
operating temperature is satisfactory, the coolant bottle
need only be checked once a month.
MAINTAINING YOUR VEHICLE 335
7

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: Often fluids such as oil, power steering fluid,
and brake fluid are used during assembly plant opera-
tions to ease the assembly of hoses to couplings. There-
fore, oil wetness at the hose-coupling area is not neces-
sarily an indication of leakage. Actual dripping of hot
fluid when systems are under pressure (during vehicle
operation) should be noted before hose is replaced based
on leakage. NOTE:
Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.
WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
Brake Master Cylinder
The fluid level in the master cylinder should be checked
when performing under hood services, or immediately if
the “Brake Warning Light” shows system failure.
338 MAINTAINING YOUR VEHICLE

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: Often fluids such as oil, power steering fluid,
and brake fluid are used during assembly plant opera-
tions to ease the assembly of hoses to couplings. There-
fore, oil wetness at the hose-coupling area is not neces-
sarily an indication of leakage. Actual dripping of hot
fluid when systems are under pressure (during vehicle
operation) should be noted before hose is replaced based
on leakage. NOTE:
Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.
WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
Brake Master Cylinder
The fluid level in the master cylinder should be checked
when performing under hood services, or immediately if
the “Brake Warning Light” shows system failure.
338 MAINTAINING YOUR VEHICLE

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)
•More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
•Taxi, Police, or delivery service (commercial service)
•Trailer towing
•Off-road or desert driving
320 MAINTAINING YOUR VEHICLE

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)
•More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
•Taxi, Police, or delivery service (commercial service)
•Trailer towing
•Off-road or desert driving
320 MAINTAINING YOUR VEHICLE

Crankcase Emission Control System
Proper operation of this system depends on freedom
from sticking or plugging due to deposits. As vehicle
mileage builds up, the PCV valve and passages may
accumulate deposits. If a valve is not working properly,
replace it with a new valve. DO NOT ATTEMPT TO
CLEAN THE OLD PCV VALVE!
Check ventilation hose for indication of damage or
plugging deposits. Replace if necessary.
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

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 radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.
Cooling System — Drain, Flush, And Refill
At the intervals shown on the appropriate “Maintenance
Schedule” the system should be drained, flushed, and
refilled.
If the coolant solution is dirty or contains a considerable
amount of sediment, clean and flush with a reliable
cooling system cleaner (see your authorized dealer for
recommendations). Follow with a thorough rinsing to
remove all deposits and chemicals. Properly dispose of
old antifreeze/coolant solution.
332 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 Hybrid Organic Additive Technology (HOAT)
antifreeze/coolant is a regulated substance requiring
proper disposal. Check with your local authorities to
determine the disposal rules for your community. To prevent ingestion by animals or children, do not store
HOAT antifreeze/coolant in open containers, or allow it
to remain in puddles on the ground. If ingested by a
child, contact a physician immediately. Clean up ground
spills immediately.
Engine Coolant Level
The coolant recovery bottle provides a quick visual
method for determining that the antifreeze/coolant level
is adequate. With the engine idling, and warm to normal
operating temperature, the level of the antifreeze/coolant
should be between the ranges indicated on the bottle.
The radiator normally remains completely full, so there is
no need to remove the radiator cap unless checking for
antifreeze/coolant freeze point or replacing coolant. Ad-
vise your service attendant of this. As long as the engine
operating temperature is satisfactory, the coolant bottle
need only be checked once a month.
MAINTAINING YOUR VEHICLE 335
7

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: Often fluids such as oil, power steering fluid,
and brake fluid are used during assembly plant opera-
tions to ease the assembly of hoses to couplings. There-
fore, oil wetness at the hose-coupling area is not neces-
sarily an indication of leakage. Actual dripping of hot
fluid when systems are under pressure (during vehicle
operation) should be noted before hose is replaced based
on leakage. NOTE:
Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.
WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
Brake Master Cylinder
The fluid level in the master cylinder should be checked
when performing under hood services, or immediately if
the “Brake Warning Light” shows system failure.
338 MAINTAINING YOUR VEHICLE