OK...the deal is, after running the car for about 1/2 an hour the motor gets pretty hot. The other day when I got home I parked the car and noticed a bit of smoke coming out from under the hood. I immediatly opened the hood. No fire! I looked under the car and a small pool of antifreeze had collected under the motor on the passanger side. The smoke was from antifreeze leaking on to the pipes coming off the motor. In total I lost about a liter. The coolant only leaks out when the motor heats up. Any thoughts on what it might be? BTW the car is a 1987 420SEL with 99,991 miles on it.