2006 Prius Rattling / Buzzing while breaking and accelerating? Is It normal?

That isn't normal!

 

that almost sounds like a transaxle whine....and that would not be normal.

best case scenario....you've got bad tires.

 

No problems Alper. The main noises I can here are:

1. A little bit of a rattle from 0:04 to 0:07 and
2. A bit of whining as you decelerate, most noticeable from about 0:12 to 0:15.

Not sure what the minor rattle is, but that whine when you decelerate is totally normal in my experience. I believe it's just the sound of the inverter and electrical machines under heavy (regenerative) loading. I've driven several Gen2 Prius and every one of them has made that whine under firm regenerative braking.

 

While the car is at a stop, repeatedly press the brake pedal. This forces the brake actuator pump to run. How does that noise compare to the rattle noise in your video?

 

Try to hitting gently or pushing dash top glove box lids and so on to make sure it’s not something in there rattling. Also check that it isn’t brake pump as Patrick Wong suggested.

 

Then you shouldn’t worry about it.

 

it's a normal sound made by the actuator pump to build up pressure on the brakes. You'll normally hear it every 2nd time you press the brakes.

 

yes that happens too

 

The Prius gasoline engine turns off from time to time, in normal hybrid drivetrain operation. Since the engine is not always running, the typical engine vacuum-operated power brake system would not work well with Prius or other Toyota hybrids.

Hence the need for the brake actuator pump which is powered by an electric motor and makes the characteristic rattle noise. That noise is normal and is no cause for concern.

 

yes. you'll hear it more during braking than accelerating

 

You will just have to be desensitized to the sound like all the rest of us.

EDIT: You can also rest assured that your brakes will function correctly whenever you need them. That is what the sound tells me.