Smoking 1989 new yorker?

If it's the engine oil that's leaking on to hot exhaust parts, that's one thing that causes smoke. There are engine crankshaft seals that can leak under the car and the oil blows back on to the hot exhaust pipes and causes smoke under the car. Which seals are leaking? It makes a big difference in the cost to repair and the time it takes. If the smoke is coming out the tail pipe at the rear of the car rather than from under the car when your parked and idling the motor, then your engine is wearing and you should probably just keep putting extra oil in the engine as long as it doesn't burn more than one quart every 300 miles. At that point, get a new car.