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Inverter coolant loop question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by philipc, Jan 19, 2022.

  1. philipc

    philipc Junior Member

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    I'm hoping someone will be able to give me some idea on what should be my next steps to loop at with my inverters coolant loop.

    Back in October during my normal look over of the car (2006) i noticed that the inverter loop had very near no movement in the reservoir and with it still on its original pump (from what i can find owned it since it 2009 and i know i've not done it) i went ahead and replaced the pump. After replacement the flow improved but still nowhere near the flow i see in videos where others are checking.

    The car currently has 240,000km and had all the coolant changed at the 160k mark as per the recommended interval. Replaced with toyota's super long life from the dealer.

    There is no air bubbles trapped as i even just today triple checked and bleed the loop again letting it circulate through the bleeder for 5 minutes. There is what i could consider decent flow through the bleeder, what i consider decent is a steady stream of fluid through the 1/8th inch (i think) hose with the bleeder "wide" open.

    I guess my question comes down to what others would recommend i look at next instead of going on a wild goose chase to get improved flow (if anything). Do i need to do a coolant flush/ change? Seems like it would be too early and the fluid looks like new still. Is there some sort of temp restrictor that it wont let fluid flow while its too cold? dont think there is but with it being -10C thought worth asking.

    I've seen other posts about the inverter fins getting blocked, but i would consider the system as maintained to the degree that i wouldn't expect build up. If thats the case anything doable to remedy?

    I dont want to wait till i get a error code for temp as if something is correctable now vs whole inverter i would like to try.
     
    #1 philipc, Jan 19, 2022
  2. Another

    Another Senior Member

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    was the replacement pump a Toyota OEM pump?
     
    #2 Another, Jan 19, 2022
  3. philipc

    philipc Junior Member

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    Yeah it was 99% sure. Read the stories about the bad 3rd party and just went with OEM. what i purchased was one off amazon came in the toyota box. Didnt buy from Toyota though.

    I have till the end of the month to get it replaced if it could be a faulty new pump.
     
    #3 philipc, Jan 19, 2022
    Last edited: Jan 19, 2022
  4. Tombukt2

    Tombukt2 Senior Member

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    I have an OEM in my '06 and a fake in my '09 between the two I can't tell by looking at the part or at the flow in the jug both look about the same make about the same amount of noise all of it The test is go out and get the car hot and make sure that coolant hoses that involve the inverter are all the same temperature in other words the coolant is moving through the bottom of the inverter and making its complete loop if it is the hoses will be the same temperature pretty much In other words all warm when my pump was out underneath my inverter would be toasty warm but the lines going to and from the pump were room temperature at best or ambient temperature and that's how I knew I wasn't moving the coolant
     
    #4 Tombukt2, Jan 19, 2022
  5. philipc

    philipc Junior Member

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    is a capture i just did in my garage, you can see movement but its like someone is lightly stirring the fluid at best. When it got colder this past week (and the car wasn't in the garage) there was even less motion. This doesnt match what i've seen in the past on this car but not sure if its weather related (cold) or a blockage or bad pump.

    As for a temp difference i haven't been able to feel much of a difference but also dont do super long drive any more and its cold out which would also likely hide any difference (i think at least)
     
    #5 philipc, Jan 19, 2022
  6. SFO

    SFO Senior Member

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    As a single data point, mine never looked that turbulent before or after a pump change, at least when compared to some others on here.
    Unlikely that the inverter would fail if you threw a P0A93, unless you continued to drive it hard while hot. Let it cool, or drive under 40ish kph.
     
    #6 SFO, Jan 19, 2022
  7. mr_guy_mann

    mr_guy_mann Senior Member

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    I installed a (from my local dealer) genuine inverter pump earlier last year. In summer there was visible "turbulence" and agitation. Now in winter I can barely tell that the coolant is circulating- but it is.

    Whether you have a genuine OE part or a counterfeit, I can't say (amazon might be slightly better than ebay- maybe), the proof is in the inverter temps when under load.

    Posted via the PriusChat mobile app.
     
    #7 mr_guy_mann, Jan 19, 2022
  8. edthefox5

    edthefox5 Senior Member

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    Yes pretty good odds the pump is counterfeit. Chinese got the box down. You must buy the part from a Toyota dealer online I have used Olathe Toyota there great they answer the phone very helpful highly recommend.

    I have only bought parts from Olathe over the last 14 years and never experience the nonsense I see on this site.

    If Im reading right first change of coolant at 160000 miles is not correct and
    Very poor.You may have some blockage.

    My car has very aggressive inverter circulation. Coolant looks like it’s boiling.

    I changed my coolant every 50000 miles. I usually did it when I changed the trans fluid too.

    I also recommend adding a bottle of Redline water wetter it works great. It’s an excellent anti corrosion additive and surface surfactant. Google it.
    I run that in the inverter and ice coolant. Inverter temp cooling improved from stock by about 10 degrees.

    I also bypassed the coolant loop on the throttle body but I don’t recommend that in cold areas of the world.
     
    #8 edthefox5, Jan 20, 2022
  9. philipc

    philipc Junior Member

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    160,000km or about 100,000miles per the factory service interval. Im at about 80,000km since the last change and will likely do another change this weekend coolant is cheap and will get the pump replaced under amazons policy. Hopefully that will improve the flow.

    I did take it for a drive yesterday but both the line in and line out were cold to the touch which i dont think is totally out of the question as it was -20C.
     
    #9 philipc, Jan 20, 2022
  10. edthefox5

    edthefox5 Senior Member

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    I think that factory service rate is way off base on the Inverter. If you looked at your inverter coolant in a clear container at just 30,000 miles you would see how contaminated it was with aluminum in solution. Nothing more corrosive than that.

    And it cant be cold to the touch no matter what the ambient temperature is. You have no circulation there. The inverter coolant temp runs about 100 degrees cooler than the engine so 80 F is right around where a healthy Inverter coolant loop lives. It does a crazy heat soak when you turn the car off as there in the same radiator though. Like a 50+ degree increase in heat temporarily. Toyota engineers saw that so they made the ice coolant and Inverter coolant separate rads in subsequent gens. They probably had to with the increased power of the electric motors.
    .
    I have done alot of testing with an IR thermometer.

    And If you bought a pump from Amazon its probably junk. Hence your result.
     
    #10 edthefox5, Jan 20, 2022
  11. Tombukt2

    Tombukt2 Senior Member

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    When I change the coolant pump on the '09 with a junkie $24 pump from Amazon or eBay or somewhere these pumps like I said before very similar and made just like the ones on some of my water-cooled power sports equipment Very simple no shaft penetrates the plastic impeller similar to a washing machine drain pump and when I replace the pump and put the new one on I see movement but it is not anything horrendous loud or any gigantic move of water by any stretch of the imagination just by the outlet and inlet size and the impeller size of the pump itself pretty small so I wasn't expecting to see water moving like gangbusters and then now with the new pump and a good rundown the road all the tubes are reasonably warm about 80 or 95° like you said and that's that when that crappy shitty non Toyota pump fails power replace it with another it goes too fast to pay much over 50 or 60 bucks for them

    SM-A715F ?
     
    #11 Tombukt2, Jan 20, 2022
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