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08 Prius Inverter Pump Replaced - Super Loud?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by burns777, Oct 8, 2021.

  1. burns777

    burns777 Junior Member

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    Just had inverter coolant pump replaced. The hum of it running is super loud and constant. The sound was never like this prior (had car for 3 years now). For example, sitting at a red light, if this engine was off then the car was totally silent. Now, all I hear is this pump running all the time.

    It is after market pump that was installed by a local mechanic. He just said, "some pumps just run louder."

    Is this normal?

     
  2. JC91006

    JC91006 Senior Member

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    The pump should not be making noise, this pump is obviously not very high quality. I think you're the first to actually complain about noise of that pump on this forum.

    I would insist on a replacement.
     
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  3. burns777

    burns777 Junior Member

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    Thanks for the help, JC91006.
     
  4. Another

    Another Senior Member

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    Maybe ask mechanic what make and model pump he chose
     
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  5. bisco

    bisco cookie crumbler

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    replace with oem, there's a lot of junk out there
     
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  6. koco

    koco Member

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    Was the system bled to get air out?
     
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  7. burns777

    burns777 Junior Member

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    Yes. That was actually an ordeal. They didn't bleed it well, so I kept getting random warnings. They bled it again and it was better, but still issues. Took to Toyota and they got it straightened out. Frustratingly, Toyota didn't look into the noise issue like I asked, just bled the system properly. By the time I went to pick it up, I pushed on the noice issue and the service rep basically said I could schedule another appointment and they'd just replace it with a Toyota pump. Was end of a long day, so I just left.

    Thanks everyone for the help!
     
  8. mr_guy_mann

    mr_guy_mann Senior Member

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    I have been amazed at how loud even a good pump can get until you get ALL the air out of the inverter cooling system.

    Posted via the PriusChat mobile app.
     
  9. ChapmanF

    ChapmanF Senior Member

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    It might also be worthwhile to look at the mounting. The original pump will have big rubber grommets.The grommets typically have a metal sleeve on the inside, so the mounting bolts tighten down onto the sleeve and no further, and the rubber is left free to soak up the vibrations. Or a bolt with a shoulder, the height of the grommet, is used to similar effect.

    A third-party pump might not come with as good hardware for dampening. There can also just be a common assembly error, leaving the sleeves out of the grommets, or using shoulderless bolts, so that the rubber grommets get cinched down hard under the bolts, and then transmit a lot of sound.

    I bought a Prius from a rebuilder once with a super loud pump, and that's what I suspect the cause was, though I didn't have it long enough to get in there and look.
     
  10. pasadena_commut

    pasadena_commut Senior Member

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    What you are saying is true, that if the rubber isolators are left off noise from a pump will be louder, but my feeling is that it will only be audible in the car, rubber or no rubber, if the pump is already making more noise than it should.

    Perhaps the installer just didn't tighten all (any?) of the bolts down firmly? Even a normal pump might bang around if it wasn't fastened down well. I recall that the back bolt was a bit of a PITA to access. Anyway, if the OP can (safely!) get a finger on the pump while it is running it should be possible to tell if it is vibrating internally or moving in place. That is, if it is loose pushing down on it should make it quiet and eliminate most of the vibration. Normal ones vibrate a little when properly installed, and pushing on them a bit will not change that.
     
  11. ChapmanF

    ChapmanF Senior Member

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    Nah ... a perfectly happy pump will still sound like some weird industrial movie soundtrack if the rubber mounts aren't right.