I parked the little dear in the garage about 9:30 last night. I went into the garage this morning around 6:30 and I noticed how still and quiet it seemed. I then opened the garage door and went outside for a few minutes. When I came back in, I hear a low whirring sound. I went back outside to listen, but it was definitely coming from the Prius, perhaps near the back, underneath. The hatch was open; I closed it, but the sound didn't change. The fob was in the house, and I didn't open the driver door, so it wasn't the brake pump. It lasted at least 2-3 minutes, at which time I was too bored to continue listening, and I went back to weeding and watering. What is it?
Maybe the HV battery fan? Was it really hot in the garage? I wouldn't expect anything in the car to be 'whiring' if the car had been sitting untouched all night.
The Prius fuel system periodically checks for evaportation leak and makes a hissss, whirl sound. No fuel vapor is being discharged; it's only a system verification check. This normally occurs about 5 hours after turning off the car. (page 22 of manual). This may not be your noise, but it's a noise that occurs from underneath the rear of car. P.S. Thanks for O Henry feedback
I thought it sounded like a fan. The garage was perhaps 80-85, and outside was cooler (70ish) when I opened the door. I wondered if the temperature change tripped the whatever-was-whirring.
I have heard the same sound when opening the driver's side door with the car parked in a cool garage (63 + or - degrees). This phenomenon has happened several times over the past several months, so I figured it was normal.
Opening the driver door after the Prius has been turned off for a period activates the brake pump. Is this what you hear? Otherwise, I may not understand what y'all are hearing.
No, I did not open any car doors, and I know what the brake pump sounds like. It stops after a few seconds. This whirring lasted several minutes but seemed to start after I opened the garage door, so I wonder if it were related to a change in the air temperature.
