2004 Jeep Liberty Owner's Manual - Page 297

MAINTAINING YOUR VEHICLE 297 Engine Timing Belt - 2.4L Engine Replace the engine timing belt at the intervals described in the appropriate maintenance schedule. Ignition Wiring System - 2.4L Engine Replace the ignition cables at the intervals described in the appropriate maintenance schedule. 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 compartment before starting the vehicle with the air cleaner removed. Failure to do so can result in serious personal injury. 7