Sometimes when I accelerated i feel vibration and resistance from the pedal. Resistance feels similar to go up hill. It sounds and feels like the car doesn't have enough power. This is on flat surface as well. Rpm's stay around 2 1/2 and then goes back down below 2. The vibration remains even as the car approaches 40 - 50 miles then no longer noticible around 60mph. If i have to stop the process repeats. The whole noise and problem is intermittent.