1998 Pontiac Bonneville Owner's Manual - Page 349
1998 Pontiac Bonneville Manual
Page 349 highlights
Long Trip/Highway Maintenance Schedule 100,000 Miles (I 66 000 km) Inspect spark plug wires. An Emission Control Service. Replace spark plugs. An Emission Control Service. Change automatic transaxle fluid and if the vehicle is mainly driven filter under oneor more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. Ifyou do not use your vehicle under any of these conditions, the fluid and filter do not require changing. DATE I MILEAGE 150,000 Miles (240 000 km) Drain, flush and refill cooling system (or every 60 months since last service, whichever occurs first).See "Engine Coolant"in the Indexfor what to use. and Inspect hoses. Clean radiator, condenser, pressure cap neck. Pressure test the cooling systemand pressure cap. An Emission Control Service. 7-30