Engine Oil Leaking problems of the 1999 Ford Aerostar

The motor would die and then accelerate suddenly, sometimes making a cranking noise. The service report stated that there no problem. In addition, when the vehicle was parked and wanted to change from parking to drive, it would be stuck, making it difficult to change the transmission, usually producing a loud cranking noise as if the transmission was to explode. Eventually, in February 2005 the motor broke down and both the motor and transmission had to be replaced. The dealer (bayamon Ford) replaced the motor in March 2005 and when the transmission was received it was replaced in April 2005. The dealer had requested the new parts directly to the Ford motor CO. And stayed with the parts replaced. The motor and transmission had full three year guarantee since they were new. The vehicle started experiencing again the dying and acceleration approximately one year after. The vehicle was left at the dealer, mentioned above on June 2006 for filter and oil change, they found that the motor was leaking oil and they took down the motor and transmission to repair the leak. After the service the check engine light turned on prior to the July fourth weekend. They informed us to bring the car on July 5. On July 4, 2006 the car suddenly accelerated beyond control and crashed. Total loss. The air bags never came out and the car stayed engine accelerated.