I just purchased a new '06 prius, but noticing a strange electric sound (a low buzzing sound) coming out from the front dashboard near the steering wheel. The sound goes on and off irregularily, but happens mostly while driving locally and making turns. I suspect this is a noise of the battering doing some work, but not sure if it's supposed to be like or there's something wrong with my car. Does this happen to any of you guys? Any suggestion?

 

That sounds slightly abnormal, probably best to have the dealer check that.

 

Try to find something that recreates the problem at will. For example, can you reproduce it by operating the fans?

You might also try to use a tape or MP3 recorder to capture the sound. This will make it easier to let the repair folks know what you are hearing.

There are so many things that can cause 'noise' it would be impossible to list them all. Mostly, you need to see if anything is associated with the sound. For example, does it stop when the vehicle stops? Are there some speeds where it seems to happen more often?

GOOD LUCK!

Bob Wilson

 

It's hard to tell based on your description.
On my 05 Prius II - and I have heard others report this sound as well - there is a sound coming from the front left, that sounds like an electric buzz, or a micro-compressor. It only comes on every now and then, it is hard to determine when it does. It is my understanding that this is the brake servo pressure pump, and I think it often kicks in when the ICE is turned off.
Not sure if this is in fact your sound, so it would be best to have it checked out by the delaer.

 

Maybe its a bomb placed there by an over zelous Honda owner!
<Just Kidding>

I to have heard this sound on my 04' with the engine off and locked up ie physicly parked .. Not sure what it is I hear it coming fromt the left front, it has done that since the day i picked it up. I would guestamate its normal..

If in doubt call the service dept and ask.

 

Two sounds come to mind: (1) inverter coolant pump and (2) ABS brake pulsing.

The inverter in the 01-03 Prius has a seperate radiator and coolant loop. There is a small pump located down low on the driver-side of the engine compartment that runs all the time. I can hear it by listening for it. If you raise the hood with just power-on, engine not running, you should be able to hear it easily.

If the sound level changes, it is possible that there is a loose mount or something has gotten in there to couple the sound to the frame. It is in a dark and distant place and unless you have the maintenance manual for your vehicle, you may want a service technical to check it out.

Today, for the first time, I heard the ABS pulse. A brief, somewhat rounded growling sound, I loved it. In Huntsville Alabama, the streets are unusually slippery right after a rain. I don't know if it is material, pollen or what but it is the closest you can get to 'black ice' above freezing. But if it is the ABS, you should only hear it when you brake or braking should impact or change the sound.

GOOD LUCK!
Bob Wilson

 

That sounds like the coolant storage system putting the hot coolant into the thermos for up to 3 days of instantly hot coolant ready to inject back into the engine upon startup.

 

There's nothing wrong with your car. 2003 and earlier Prius models don't make this noise because they rely on the engine's vacuum to keep the brake booster charged. 2004+ Prius models use an electric pump that periodically activates to keep vacuum replenished for the braking system to prolong ev-only driving.

It should sound like an aquarium air bubbler (if you've ever heard one) buried deep in the dash on the driver's side. It comes on every 60 seconds or so in urban driving.

To test: Turn your car off. Pump the brake pedal four or five times. If the buzzing starts, then this is normal and to be expected. Make sure to let the coolant-storage pump finish its thing after the car shuts off to avoid confusing the noises.

-Drew

 

Fantastic first post Drew. I just noticed that this is your first ever post ever at Green Hybrid and it sounds right on the money. Good job!

 

Actually they do have electric brake boosters, at least our 2001 does. Same thing happens, pump the brakes a few times and then a few seconds of buzzing with a little clicky-pop at the end... The engine doesn't turn on for more brake vacuum.