My car is an automatic, when I turn my car on the engine shakes more then normal. It is not violent but it does rattle the dashboard. When I put the car in Reverse or Drive it jerks in gear. When I am driving the car It doesn't change gears like it should. It does not have an RPM guage but I can hear that it needs to shift. I have to release the gas petal for it to shift into the next gear. Is this normal, can I do anything?