From what I understand, the around 5 second humming noise the Prius makes after the engine shuts off is the coolant heat storage pump. My car used to only make this humming noise maybe once after the engine was shut off, and occasionally when idling at a stop light. However, recently, the car has been making this noise once a minute, while driving, at a stop light, and several times after the engine is shut off. Is there a way I can troubleshoot this/fix it? There are no warning lights on. Thanks
Could be brake accumulator problems, @ChapmanF might weigh in. There is no coolant heat storage pump on third gen, just a second gen component.
Please verify for us that your car is 2010-2015 model year. Record a short video with the sound, make sure the sound is accurate, and post it to YouTube for us. Toyota May cover this at no charge, even out of warranty.
