1999 Buick Riviera Owner's Manual - Page 243

yellowblue Your vehicle has a 3800 Supercharged V6 engine. The supercharger is a device designed to pump more air into the engine than it would normally use. This air, mixed with fuel, creates increased engine power. Since the supercharger is a pump and is driven from an engine accessory drive belt, increased pressure is available at all driving conditions. The Powertrain Control Module (PCM) works with a vacuum control to regulate the increased pressure required during specific driving conditions. When this increased pressure or boost is not desired, such as during idling and light throttle cruising, the excess air that the supercharger is pumping is routed through a bypass. All of these controls working together provide high performance, character and fuel efficiency in the 3800 V6 Supercharged engine. For more information, see "Check Oil Level Light" in the Index. You should check your engine oil level regularly; this is an added reminder. It's a good idea to check your engine oil every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground. The engine oil dipstick is a round, yellow loop located directly behind the engine fan. Turn off the engine and give the oil several minutes to drain back into the oil pan. If you don't, the oil dipstick might not show the actual level. Engine Oil If the CHECK OIL LEVEL light on the instrument panel comes on, it means you need to check your engine oil level right away. 6-11