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Driving with a failed inverter coolant pump?

Discussion in 'Gen 2 Prius Main Forum' started by uart, Oct 10, 2011.

  1. uart

    uart Senior Member

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    My inverter coolant pump has bitten the dust and it's booked it in for replacement under the recall, but unfortunately they can't do it until Oct 24 (two weeks). My wife normally drives the Prius with a long commute, so she'll be taking the other car and I'll be stuck with the sick Prius (and my bicycle)..

    My question is, how risky will it be if I need to use the Prius for some short trips at relatively low speeds (35 to 40 MPH)? Current temperatures here are about 70F to 75F. I'm going to try to avoid using it as much as possible, but just wondering what the possibilities are if I get desperate.

    BTW. Currently it hasn't overheated or thrown any codes. I must have noticed it nice and early before any problems occurred.
     
  2. 2009Prius

    2009Prius A Wimpy DIYer

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    My guess is it would be OK. Don't block the grill. Patrick had a suggestion to put a bag of ice on top of the inverter.
     
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  3. uart

    uart Senior Member

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    Interesting suggestion about the ice. :cool:

    I took it for a 10 mile drive today and when I got home felt all around inverter with my hands and I couldn't feel anything uncomfortable to touch. It was warm to touch around the sides and underneath but nothing that seemed dangerous.

    I wonder how efficiently heat is transferred from the working electronics to the case of the inverter. I get the feeling that there's not really that much thermal connection to the top (silver) cover.
     
  4. 2009Prius

    2009Prius A Wimpy DIYer

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    If you got time it would be really nice to have PriiDash or Torque set up and record temperatures before and after the pump change.
     
  5. firepa63

    firepa63 Former Prius Owner

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    How do you know the pump has failed? Did you check the coolant tank with the car in IG-ON?
     
  6. seilerts

    seilerts Battery Curmudgeon

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    You are fine as long as it is from a cold-start. The risk is not so much the inverter/trans overheating as having the car die when the DC converter shuts down and the subsequent power demand on a weak 12V battery is too much.
     
  7. uart

    uart Senior Member

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    Yeah I've been checking it fairly regularly (about once a month when I check the oil) since I read about the recall. I could definitely see the coolant gurgling away last time I checked (about a month ago) but now there's nothing at all. It's absolutely dead still, tested it in both "ig-on" and "ready" states. Fluid levels have been maintained at correct level at all times.
     
  8. uart

    uart Senior Member

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    Thanks Seilerts, I think I'll limit to short 10 to 15 minute trips.

    BTW. Does anyone have a link to pictures of the pump, I don't even where it is on the car?
     
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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  10. Flaninacupboard

    Flaninacupboard Senior Member

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    My inverter radiator was punctured, and all the fluid was pumped out of the system. i had to drive the car about 25 miles at 60mph+ to get to the dealer. I received the Check Hybrid System warning, but it did not overheat. The car did however run in a horrible way, it must have gone into some sort of protection mode, because even the smallest change in pedal pressure caused the revs to instantly go up and down, and it felt generally lumpy and unpleasant to drive, especially at low speeds as the engine didn't seem to want to shut down.
     
  11. uart

    uart Senior Member

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    Yeah I'd imagine that running with fluid, even without pumped circulation, is a lot better than running without any fluid at all.

    So far I've been lucky enough to not have any performance issues, so it must have stayed below some temperature threshold.
     
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  12. uart

    uart Senior Member

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    Thanks Patrick, that helped mt locate it. I really just wanted to be certain I hadn't just knocked the electrical connection loose or anything.

    BTW. I tried to unplug and then replug the connector but I couldn't get it free. Is there a trick to removing the electrical plug?
     
  13. andyprius

    andyprius Senior Member

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    In the meantime it cannot hurt to bleed the air out of the inverter pump system. Just search inverter pump, all kinds of threads.
     
  14. uart

    uart Senior Member

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    I don't think the problem is air in the system, the pump has just stopped working (no sound or vibration from it). The dealer will be replacing it soon so I don't see any need to be doing anything with it right now.
     
  15. Patrick Wong

    Patrick Wong DIY Enthusiast

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    A quote from my cited post:

    "Disconnect the wiring harness connector. You will need to squeeze the tab on the connector to release it. This is not easy to do."
     
  16. edthefox5

    edthefox5 Senior Member

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    No your wrong. The Inverter did overheat (that was the Hybrid CEL) and shut down and if you noticed discharged the hybrid battery almost to max forcing the car to run on ICE only.
    The inverter will overheat very quickly with no coolant. Btw, that coolant also cools the transmission and that overheated too.
     
  17. efusco

    efusco Moderator Emeritus
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    1)Call around to other Toyota service departments, if any, near you to see if you can get it in sooner.

    2)Consider leaving it with your chosen service department, mine initially gave me some 2 week window too, but said I could leave it and they'd try to get to it sooner...they got to it in 2-3 days and I just used a rental for that time frame.

    3)While the very short trips, without AC and minimizing regen (put the car in neutral before hitting the brakes) in low/moderate temps probably is OK I would not exceed a trip of more than 5-6 miles and then allow quite a while for the inverter to cool down before driving again. I can tell you first hand that the inverter temps rise very high very quickly (monitored with CAN-View) and a burned up inverter will cost you a LOT more than a rental car.
     
  18. Troy D. in Arizona

    Troy D. in Arizona New Member

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    The inverter coolant pump is fist-sized plastic and is behind one of the headlights. I learned the hard way that you better replace it regularly, before it blows as when it blows it can burn our your inverter which dealers charge $3000 for plus labor. Good luck finding a shop that knows how to put in a used one (Check Car-Parts.com) which you can find for $800 and up.
    My Toyota dealers never warned me once about the danger of pump failure causing such an expensive repair. Just never crossed their minds, huh, as I brought it in for inverter coolant changes. So now, instead of just changing a cheap pump, the dealer is requiring me to buy a new inverter, plus labor for total of more than $4000. Thanks for nothing, Toyota. I invest in this vehicle and this is the best advice your dealers can give me? No warnings at all. For honest advice, check out Luscious Garage in San Francisco, which services the S.F. Prius taxi fleet along with all the bay area Priuses. They have a good web site. They told me more about the Prius than my dealers ever did.
     
  19. Flaninacupboard

    Flaninacupboard Senior Member

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    No it didn't drain the hybrid battery, there seemed to be no charge or discharge happening at all (remained at 6 bars, no arrows going either into or out of the battery on the MFD)
     
  20. uart

    uart Senior Member

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    Thanks everyone for the advice. I did heed the warnings and have only used the Prius for very short trips over the past week.

    Today the pump was replaced under the LSC at no cost ) and I'm pleased to say that the coolant is circulating once again. :D