My issue is the first 20 miles or so the transmission runs fine in D but after that when it's in high gear cruising it will act like it's coming out of gear and go back in making the rpm jump from 2300 to 2800 and back and slightly bumping the car but if you put it in manual mode it stops doing it right away the entire time it's in manual but if you put it back in D it's starts going it again