Just today I have observed that whenever my car is going from EV to gas, it makes these engine noises similar to those as if the engine was about to shut down and it made an extreme effort to reignite. This an extreme vibration in the car followed by a noisy engine which can be felt immensely. It occurs when I am accelerating for example at a traffic signal. I am running a 2012 Toyota Aqua (Prius C) with 57,000Km. I will be glad if the senior members of this forum can help me out. Grateful.