High Pitch Squeak/Whistle while accelerating and braking

I suspect your problem is good hearing. Your Prius uses an inverter to drive the electric motors, and the high frequency drive pulses can be heard by anyone with good hearing. It sounds like a high pitched whine, and is most pronounced while accelerating and braking.

Tom

 

I ask that the OP not post in multiple forums on the same subject.
http://priuschat.com/forums/gen-ii-...-pitch-squeak-while-accelerating-braking.html

In any event, I agree that the inverter is the most likely source of the noise noted. Perhaps the 2007's inverter has a slightly loose component which results in better sound production.

 

The inverter is functioning whenever the Prius is READY. Perhaps you can have someone rev up the engine while the car is parked, so that you can stand by the engine compartment and listen around to see whether the sound is coming from the inverter or elsewhere.

 

Good to know! Thanks for the update.

 

Our Prius - which we love dearly - sometimes emits a high pitched whistle, a sound very much like the one when you are sharpening an ax on a grindstone. There seems to be no rhyme or reason to it: it can happen in town (ie at low speeds) or on the motorway, when accelerating, or when slowing but NEVER when standing still. Our Toyota dealer has checked it out (without taking it out on the road) but says there's nothing wrong. Hope they're right as we're about to drive some 3,000 miles on holiday and and ear-piercing whistle for all - or any part of that - would be craze-making.

 

Our Prius - which we love dearly - sometimes emits a high pitched whistle, a sound very much like the one when you are sharpening an ax on a grindstone or astone caught in the brakes. There seems to be no rhyme or reason to it: it can happen in town (ie at low speeds) or on the motorway, when accelerating, or when slowing but NEVER when standing still. Our Toyota dealer has checked it out (without taking it out on the road) but says there's nothing wrong. Hope they're right as we're about to drive some 3,000 miles on holiday and and ear-piercing whistle for all - or any part of that - would be craze-making.

 

has checked it out (without taking it out on the road)

Take it back to the dealer and have them drive it on the road. If the sound happens more often when warmed up, drive the car some before the visit. As the inverter is a likely cause, have the technician load the system with running the A/C and headlights. Be persistent , perhaps ride along during the test drive.

I wouldn't drive the car making a noise like that on a long trip, its not just annoying, its risky in my opinion..

 

Hi sufyant,
I think I am having the same problem, but unfortunately my Prius is not under warranty any more. Did you get an idea of how serious the problem is for the overall performance of the car? Is it dangerous to drive? Thanks.
Joseph

 

ok, thanks. any idea how much it would have cost you to replace the inverter if yours hadn't been under warranty?

 

I'm hearing something similar in my 2010 prius. What about an inverter flush? Would that work or does the whole thing have to be replaced?

 

Might be an idea to ask your question in a Gen 3 forum. What appears to be the same, may be not applicable across generations.