I have a Toyota Corolla that hesitates when accelerating from a stop point, ie from 0-20kmph. Then, speed is normal above 20kmph.
A description of the sound would be: engine rises and so does the RPM(4k-5k) but the car is accelerating slowly until the speed reaches 20kmph. Then, the engine sound drops and so does the RPM(1). Then, the car would be accelerating fine above 20kmph.