Yes, this is another posting about peculiar under-hood noises. Sorry. I think my 2009 Prius has occasionally made what I call "the sawing sound" since I purchased it new. (It now has 134k miles on it.) For you young pups who think all saws have round spinning blades, I hail from a bygone era where trees were felled by hand using a two-man crosscut saw. My Prius now emits this hand sawing sound continuously. It's no longer an intermittent thing. Is this sound the that posters often refer to as the Barking Seal Noise? If not, what is it? Does the fact that the sound is now continuous while the vehicle is running mean that brake failure is pending? I just received my first notice from Toyota about warranty extension for brake pump problems. Does this warranty extension pertain to my sawing noise? Jim in Indianapolis
I'm guessing 3-way valve, too. Mine made noise for a few years before throwing the code. The valve lives under the inverter in front of the left front fender. You can use a length of heater hose as a cheap stethoscope.