Jeep Liberty 2007, Owner'S Manual, Page: 324 / 417

Special tools are required to properly measure tension
and to restore belt tension to factory specifications. Also,
check belt routing to make sure there is no interference
between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the mileage specified in the appropriate main-
tenance chart. The entire set should be replaced if there is
any malfunction due to a faulty spark plug.
Refer to the “Vehicle Emission Control Information” label
in the engine compartment for spark plug information.
Spark Plug Wires
The spark plug wires should be kept clean and properly
connected. Terminals should be fully seated. Cracked,
damaged, or faulty wires should be replaced.
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 induction system (air cleaner, hoses, etc) can
provide a measure of protection in the case of engine
backfire. Do not remove the air induction system (air
cleaner, hoses, etc) unless such removal is necessary
for repair or maintenance. Make sure that no one is
near the engine compartment before starting the
vehicle with the air induction system (air cleaner,
hoses, etc) removed. Failure to do so can result in
serious personal injury.
324 MAINTAINING YOUR VEHICLE