1998 GMC Safari Owner's Manual - Page 340

Maintenance Schedule I Short Trip/City Intervals . I I Long Trip/Highway Definition I Every 100,000 Miles (166 000 km): Spark Plug Wire Inspection. Spark Plug Replacement. Positive Crankcase Ventilation (PCV) Valve Inspection. Every 150,000 Miles (240 000 km): Cooling System Service (or every months, whichever occurs first). 60 These intervalsonly summarize maintenance services. Be sure tofollow the complete maintenance schedule on the following pages. Follow this maintenance schedule if none of the only conditions from the Short TripKity Maintenance Schedule is true.Do not use this schedule if vehicle the is usedfor trailer towing, driven in a dusty area or used off paved roads. Use the Short TripKity schedule for these conditions. Driving a vehicle witha fullywarmed engine under highway conditions causes engine oil to break down slower. 7-6