I have a 1998 Buick Century. Yesterday while driving the car's oil light would turn-on when I stopped at a stop sign and when I accelerated the oil light turned-off. I pulled into a gas station and checked the oil, maybe a qt low, so I added oil. The oil light stopped turning on and off. I got on the freeway (no oil light on) and drove for 5 miles or so when the car lost power and I pulled off the freeway. I had the car towed to a mechanic who told me the car needed a new oil pump and two cylinders had no compression. He said the only way he could tell if my engine was not damaged was for me to spend $650 on installing a new oil pump. Another friend told be that a 1998 Buick Century has a relay switch and that perhaps the switch was bad and that caused the car to turn itself off. When the car decelerated there was no smoke, no engine noise etc. it just decelerated to a stop and would not restart.