Constant Inverter Clicking / Buzzing Noise when car in 'ready' mode

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Michael Wadley, Oct 1, 2022.

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  1. Michael Wadley

    Michael Wadley Junior Member

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    2007 Prius
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    Touring
    My 07 prius makes a clicking / electrical buzzing noise at a constant interval of every second or two, and it appears to come from the inverter (or something below it). The noise is made probably ~90% of the time the car is in ready (makes the noise regardless of whether or not the ICE is running or not). It is a fairly quiet noise, can barely be heard inside the cabin with the windows closed, and is almost impossible to hear when the ICE is running.

    Here is a video of what the noise sounds like: https://youtube.com/shorts/pt5hbhe1IVs?feature=share

    I don't believe the vehicle has always made this noise, but I can't say for certain when it began happening since I likely didn't notice it for a while because it is so quiet. I first noticed it about a month and a half ago, and have driven the car since then without any apparent issues (other than the deteriorating hybrid battery that I am delaying replacing). The car does burn a lot of oil, maybe 1-1.5 quarts for every 1250-2000 miles, but everything else should be in good shape. I did check the inverter coolant reservoir and it is turbulent and obviously has moving fluids inside when the car is running. The last work I did on the car was installing a new 12v battery, nearly 2 months ago, which was no issue, and I don't think that has anything to do with it.

    Hopefully someone can help me understand why my car is making this noise, let me know if it will cause damage if I continue to drive it while it makes this noise.
     
    #1 Michael Wadley, Oct 1, 2022
  2. Tombukt2

    Tombukt2 Senior Member

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    It almost sounds like an inverter pump or one of the pumps there's like three on the car that move the equivalent of antifreeze around the different systems That's what it sounds like to me even allowing for the poor microphone of the phone or whatever the heck's going on but I not heard anything like that before I don't think usually the inverter pumps in the pumps just stop pumping and you don't get any noise and you get nothing
     
    #2 Tombukt2, Oct 1, 2022
  3. PriusCamper

    PriusCamper Senior Member

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    Some people describe this as the sound of an old floppy disk drive... It's your 3 way coolant valve. The sensor inside it wears out and gets confused. Fairly common problem. You'll get a check engine light eventually for it. Also usually your coolant heat storage pump that you can hear running most of the time after you turn off your car will stop working when this part fails. They're fairly cheap to replace and if you got 3 really good large diameter hose clamps you can swap it out without having to drain the coolant. Here's the one I most recently bought. It's an aftermarket part, not an over-priced OEM one, but IMHO folks who make 'em make high quality parts: https://www.ebay.com/itm/394097566363
     
    #3 PriusCamper, Oct 1, 2022
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  4. Tombukt2

    Tombukt2 Senior Member

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    In my 05 the pump that went to the tank in fender failed . I removed the other same looking pump from another car same looking pump but marked 14.1 instead of 12.0V from in-between the brake actuator and master cylinder thingy . Runs better stopped all noise too. Also used this exact pump as inverter pump no fails since both of these 14.1 pumps are old as dirt from 300K mile cars.
     
    #4 Tombukt2, Oct 2, 2022
  5. Michael Wadley

    Michael Wadley Junior Member

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    2007 Prius
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    Touring
    I think you are right, I was able to find other videos people posted online of a "floppy disk sound" in the prius, that sound exactly like the sound I am hearing. Thank you very much for the help!
     
    #5 Michael Wadley, Oct 18, 2022
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