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Mechanic says the inverter is failing and water pump is leaking, what should I do?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MiaTwo, Nov 13, 2019.

  1. MiaTwo

    MiaTwo New Member

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    The 2008 Prius I just bought makes a loud buzzing sound. Took it to a mechanic to have them do a full diagnostic, and he said the inverter was failing, and also the water pump has a leak.

    He didn't seem to know a ton about hybrids however and admitted he doesn't work with them much himself, so I wanted to ask if there's a way for me to diagnose it and be sure that's what's wrong before committing to replacing it?

    Is it dangerous NOT to replace it if so? He said it could cause the car to just shut off. Would it be a dangerous situation where the brakes wouldn't work, or would it be more likely to fail to start after shutting off the system?

    I see there are places to buy the part for $150 used. Should I do that and learn to replace it myself?

    Also, when replacing the leaking water pump, what do I need to buy? I see cheap plastic pieces for $35, and quotes that say a water pump replacement can cost $800 for parts. I don't want to buy the wrong thing. From what I read there are 4 water pumps in the second gen prius, but 3 are electric and 1 is mechanical. So I would replace the mechanical one?

    Any advice would really help. I'm completely new to hybrids and trying to figure this out as I go, but I don't understand enough to know where to start, though I do have some limited experience doing basic car repairs, but nothing too advanced.
     
    #1 MiaTwo, Nov 13, 2019
  2. JC91006

    JC91006 Senior Member

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    I'd suggest you get another opinion as this one doesn't really count. The person already told you he doesn't work with hybrids.

    Inverters rarely fail on the 2nd generation Prius cars and the water pump that's driven by a belt, is about a $60 part on Ebay if you want to DIY the repair. A dealer will charge about $500 for this repair.
     
    #2 JC91006, Nov 13, 2019
  3. pasadena_commut

    pasadena_commut Senior Member

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    When does it "buzz"? Only when it shuts down and starts up? These cars make a reasonably loud and quite odd noise while moving coolant into or out of the thermos. That is perfectly normal.

    As far as a leaking water pump, did you see evidence of that yourself? Hard to see what that would have to do with the inverter unless it was the inverter pump. Those are not at all hard to change yourself.

    How did the mechanic "know" the inverter was failing? If it was there would be a code, and he should have given it to you.
     
    #3 pasadena_commut, Nov 13, 2019
    George W likes this.
  4. MiaTwo

    MiaTwo New Member

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    There was no code. I did buy it from a mechanic who claimed there was nothing wrong with it, but I did get it really cheap so I don't know which mechanic is lying to me. That's why I was hoping there was a way I could verify it myself.

    The car buzzes whenever the air conditioning is on. It's extremely loud though, if standing outside of the car it sounds like a jet engine, much normal than a normal car. I don't know how to cheap the water pump either. Should I just watch the coolant levels? The problem is I'm hoping to take the car on a very long distance road trip soon, so I'm hoping to take care of everything that's wrong with it before that. Should I take it to a Toyota dealership? They charge a lot more money. Do you know a way to check the inverter or water pump myself, or is there definitely nothing wrong with it if there's no codes being thrown?
     
    #4 MiaTwo, Nov 13, 2019
  5. bisco

    bisco cookie crumbler

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    congrats and welcome!
    a/c compressor is making the buzzing noise. you can ignore it, and the water pump as well

    how many miles on her?
     
    #5 bisco, Nov 13, 2019
  6. M in KC

    M in KC Active Member

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    First off Welcome to PC!

    How did they arrive at their conclusion that the inverter is failing? What was their proof of concept?

    You are correct in the fact that there are more than one water pump in our vehicles. Which pump is leaking (internal combustion engine {ICE}, inverter, other)? Check your coolant level in the radiator only and not by simply looking at the expansion tank. To do so, you have to remove the 5 or 6 push pins on the large black plastic cover above the radiator. If it's the inverter coolant pump that is leaking then assessing the coolant in that separate loop is done so by evaluating the coolant level in the translucent coolant tank adjacent to the inverter. Both of these cooling loop are independent of the other.

    There are several DIYs both on PC and Youtube for replacing the water pump once you/we know which one is leaking. Generally you will observe a red to pinkish dried crystals around the offending leaking area, assuming you or the PO has used Toyota's Super Long Life Coolant in your cooling loops.

    If you consider yourself a DIYer changing the water pumps (ICE or Inverter), are very straight forward. The bleeding of air out of the cooling loops after changing these pumps we where most seem to stumble. But again tons of helpful threads on PC or vids on Youtube and more knowledge about repair and servicing this cars on PC than anywhere else.
     
    #6 M in KC, Nov 14, 2019
  7. MiaTwo

    MiaTwo New Member

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    I'm not sure how he diagnosed it, and the mechanic admitted he didn't work on hybrids much. I'm going to check the coolant level periodically as you suggest, and if it's actually losing fluid then I'll replace it. Thank you so much for your help.
     
    #7 MiaTwo, Nov 18, 2019
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