1996 Pontiac Bonneville Owner's Manual - Page 350

Long Trip/Highway Maintenance Schedule I 100,000 Miles (166 000 km) E Drain, flush and refill cooling system l (or every 60 months since last service, whichever occursfirst). See "Engine Coolant'' in the Indexfor what to use. Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test the An cooling system and pressure cap. Emission Control Sewice. 0Change automatic transaxle fluid filter and if the vehicleis mainly driven under or one more of these conditions: - In heavy city traffic where the outside temperature regularly ,reaches O F 90 (32 O C ) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or 0Inspect spark plug wires.An Emission Control Service. Replace spark plugs. Emission An Control Service. delivery service. If you do not use your vehicle under any of these not conditions, thefluid andfilter do require changing. 7-35