Whirring/Winding sound under steering wheel?

[spencer999]

I've had my prius for about 2 weeks now, and I'm just now noticing a "winding" or "whirring" sound coming from somewhere underneath the steering wheel down by my left foot.

It doesn't seem to be related to anything i'm doing (braking/idling/turning/accelerating) and it only lasts about 3 seconds. but it happens several time during a trip.

Has anyone noticed htis sound? is it the "brake whine" that i've read about? or is this something unusual and i should have it checked out?

any advice would be great.

thanks!

[DaveG]

I'd guess it's probably the power inverter, which clicks, whirs, and hums occasionally.

The braking whine should be easy enough to notice, just close the windows, turn off the AC and stereo, and press light to moderately on the brakes as you're going down a hill (preferably after the engine has stopped). You'll hear a high-pitched whining noise as the generator turns the braking force back into electricity.

Or if you've listened to too much loud music, you might not hear it at all

Dave

[spencer999]

ha, yeah, considering i'm a touring musician, i probably can't hear the break whine.

i'll check out it out tho... i'm hoping this whirring sound is normal.

thanks for your comments.

[Sufferin' Prius Envy]

Spencer999, It could be the brake system’s hydraulic boost pump you are hearing. To test, put car in park and step on the brake peddle several times to bleed accumulator pressure. You should soon hear the boost pump come on to boost the pressure back up. If that is the sound you were hearing, you now know what that sound was.

[SynergyGuy]

I've heard it too and I believe this sound is coming from the power inverter and you may actually even hear it a few seconds right after switching the power off. Try opening the hood and you'll notice it. I think this is the normal behavior, it's just one of those things that's comes with this type of technology.

[htmlspinnr]

Actually it's neither.

The power steering assist motor on the '04+ is located in the column itself pretty much below the wheel inside the cabin. When you turn the motor, you're triggering a torque sensor which tells an electric motor attached w/ a worm gear to the column to provide assist. As it turns, it makes a slight whirring noise.

An intermittant whirring noise after braking or shortly after shutdown (including a bleedoff and rebuild of pressure) under the hood which seems to decrease in pitch would be the hydraulic brake pump.

Another whirring noise which occurs right after startup and before ICE start, as well as immediately after shutdown if the ICE is warm, would be the coolant pump.

HTH,
-Rick

[chrism07924]

Rick, you the man, this may be the noise I'm hearing. Now, I know why I was thinking fishing rod wheel in terms of the noise I hear.

Question I have is, why would I hear the noise when I'm not turning the wheel (i.e. on a straight away, although soon after a turn).