As you may know, the Prius has a secondary power source, a gasoline engine. I believe it is basically a Corolla engine. Sometimes when I’m idling and the secondary engine engages, there’s a “bump”. It feels like something has hit the car. One friend suggested it might be happening because of a loose engine mount. Any idea?
Actually the gas engine is the primary power source. The electric motor is secondary since this is not a plug-in hybrid, it is fueled by gas alone.
Anyway, the car can drive on EV only until the battery is drained when the engine starts These cars have always had a perceptible bump when the IC engine starts up. The 2010 was better than previous years but it was still there. The car is now 9 years old and may not start as smoothly as it once did plus, yes, a mount could be failing, or just old and hard. Have it checked out.