2001 Ford Taurus, mileage: 65,000. I have taken the car twice to the local Ford dealer (I am in Germany) for no overdrive. The transmission does not slip in any of the other gears and shifts with no problem. They said it was low on fluid which I checked before I took it in and they replaced the speed sensor with no luck. It's now in the shop and I'm hoping it will be repaired soon. Any help would be great appreciated. Thanks for your time.
Your car has a lock-up torque converter in the transmission. It locks-up only in high gear. It is supposed to engage at high speeds. Yours is probably not engaging. There could be a valve in the transmission hanging up . Having the transmission serviced with new fluid may help the problem. Next step, the valve body will have to be removed and cleaned paying special attention to the TCC solenoid. The TCC solenoid may have to be replaced.