Hey, I have an E350 1992 7.3l Diesel, with E40D and the tranmission changes the gears from the 3rd into Overdrive and back and so on, even If I drive constantly 65mph on the highway. The oil temperature increase aproximatly 20° above normal. The oil is fine and every service is done. What could it be? I thought about the TPS (throttle position sensor) but it is a diesel. If ther one, where it is? Other solution is the CPS (cam postion sensor) , but the engine runs normal with different rpm in parking position.
What about the sensor near the acceleration pedal?