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Cooling system issue after a mechanic's OOPS!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by CA2012PriusOwner, Jan 25, 2024.

  1. CA2012PriusOwner

    CA2012PriusOwner New Member

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    I recently had the sparkplugs replaced on my 2012 Prius after noticing uneven and poor acceleration.

    After the job, the car ran perfectly for a few days.

    Then I drove about 40 miles round-trip and on the way back, I noticed the heater was blowing cold air, and then just before I arrived home the temperature light and check engine light came on. I made it back home, and when I opened the hood to do a visual check, the cap of the engine coolant reservoir was not on — it was found on the cowl panel louver!

    The mechanic had added some coolant but forgot to put the engine coolant reservoir back on, and the coolant got low and caused the car to overheat.

    I don't know what damage may have occurred, but the mechanic initially thought just adding some coolant would solve the issue. Upon driving it, though, the heater was still blowing cold and after several miles the temp light came back on.

    He has determined that the coolant is not circulating properly, and he tried pressurizing the system to see if he could get it to flow but that didn't work.

    Then he removed the thermostat which he says would allow coolant flow at all times, and he hears the pump spinning but thinks the impeller is damaged "from age" and that that could be the problem.

    The car has a little over 200,000 miles on it and has been running perfectly prior to the sparkplug replacement.

    Any thoughts or suggestions on this would be appreciated!
     
  2. bisco

    bisco cookie crumbler

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    best thing to do would be to read the trouble codes with a prius aware scanner
     
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  3. ChapmanF

    ChapmanF Senior Member

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    It would not be a bad idea to go through the proper procedure for refilling the cooling system: fill the reservoir to B, put the cap on, run the engine up to temperature and several minutes longer, shaking some hoses, then shut things off and check, after it is fully cooled down, that the level has moved from B down to FULL.
     
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  4. ASRDogman

    ASRDogman Senior Member

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    He should replace the water pump and thermostat and properly fill and
    bleed the system. HE caused it, HE should pay for it!
    If he doesn't, get a lawyer, you'll win.

     
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  5. CA2012PriusOwner

    CA2012PriusOwner New Member

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    The mechanic also says he is worried that with the water pump not working for an unknown amount of time is that the head gasket may be damaged, too. He says those normally are an issue at 130,000-mile range on these years and after a block test it does have some combustion fumes in the cooling system.

    I noticed when he was trying to get coolant to flow that the exhaust seemed unusually thick white smoke, and asked him about the possibility of head gasket damage, and at that time he said he didn't think it was damaged because the oil wasn't milky.

     
  6. Tombukt2

    Tombukt2 Senior Member

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    Thermostat needs to go back in on this model if you're scared of the workings of the thermostat and don't want to ever deal with it doing anything foolish you can modify it but that's for another day. Your water pump impeller may in fact be splitting and be bad it's a real easy to check it's a two or three bolt operation somebody needs to have a look in there while you can If you call up the pump with Toyota or quality automotive software and you hear the pump chunking out that's what you're hearing the impeller's moving a little bit stopping moving a little bit stopping moving a little bit because the plastic that shrouds the metal magnet or the metal pickup of the impeller is coming apart from age and the type of plastic it is and what have you when you pull it out you'll be shocked to look at it it looks like h a l e You can buy a new one for $30 on Amazon if I'm not mistaken and when you get the new one and look at it to the old one you'll be like holy Jesus you'll drop that impeller in plug up the pump before you bolt it to the car call it up with the software make it run a few speeds see that it's turning it's quiet un call it from the software shut the mess down bolt it all up follow the procedures above fill it to the b mark drive it around run it till it drops to the f mark or what have you and see what you have from there just pray to goodness that the overheating and whatever did actually go on is not affected anything and you're not going to have the dreaded head gasket problem at 200k You are due.
     
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  7. CA2012PriusOwner

    CA2012PriusOwner New Member

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    The mechanic says he has my car fixed now, with a new water pump, thermostat, and coolant.

    He was asking me for $800!

    My response was:

    I’ve been told that if the issue was caused by the negligence in not properly securing the coolant reservoir cap, then it's reasonable to expect you to take responsibility for the resulting problems.

    I’m a believer in “the golden rule” (treat others as you would expect them to treat you) and if I was in your shoes, I would feel responsible and would repair the car to the same condition as before at my expense.

    I feel like maybe you justify sharing the expenses because the car has high mileage and these parts may already been close to or beyond their life expectancy.

    The car had no issues with the cooling system and overheating prior to this, and the problems are a result of the coolant level dropping due to the missing cap.

    Can you please give me a detailed explanation of the $800 repair cost, a breakdown of parts and labor, and how you justify placing the responsibility on me?

    His reply:

    I will eat the labor on this which is $435.

    The parts I cannot which is $382 my cost.

    The water pump failure is not able to be put on me as it's an uncontrollable failure part due to high miles on the vehicle and can happen at any time.

    You lost the flow of the cooling system with that part failing, if the cap was really off the system would still flow and provide sufficient enough cooling. The vehicle still contained coolant in the resi when I came to look at it. The pump is what makes the cooling system flow as needed not the resi cap.

    I don't fully agree with what he says, though I am not a mechanic or an expert on Prius repair, but I do think that he is responsible. By leaving that cap off, the coolant level became very low and I've read that without the resistance of the coolant that the water pump can over-rev and fail.

    Being that I do have high miles and the parts are likely beyond the average life expectancy, I am going to agree to pay the $382 for the parts to keep the peace.

    I just hope there isn't more extensive damage, i.e. head gasket, that might not be immediately evident.

    Also, in his message, he says, "if the cap was really off" which makes me feel like he's trying to deny that he even left the cap off and calling me a liar—the cap was really off!
     
  8. CA2012PriusOwner

    CA2012PriusOwner New Member

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    This is where the coolant level dropped to due to the cap being left off:

    [​IMG]
    [​IMG]
     
  9. Tombukt2

    Tombukt2 Senior Member

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    I cannot remember what your mileage is but this is what's expected is going to happen to 2010 to 2015 or so 2ZZ engine Prius so there's always that You're actually a little over the mileage for that to happen if you're above 185,000 mi so I guess you could say you could consider yourself lucky. But I guess this is a decent resolution for both of you and yes at that mileage the water pump would be nearly finished generally speaking but it's electronic it could have lasted another 5 years oh well letting the water run down that low there's still water in the resi. It's low but it's still there so all below that reservoir is still full and has the water gets hot it's going to expand and lift up into the resi. So it's not dry but the impellers go bad not from being dry just from the heat and years of time running the impeller sheds its plastic and can't spin in its bore. It's like a mag drive pump for a pond or a washing machine pump out pump so there's always that I don't generally leave caps off so I don't have this problem but I have removed the resi cap on a few generations threes to stop pressure on the water to keep it from pumping into the cylinder creating all the problems and for a while at worked till leak got worse and then the car gets parked and phased out because it's not worth fixing for us anyway.
     
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  10. ASRDogman

    ASRDogman Senior Member

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    He's correct for the labor. He's mostly wrong for the parts failure.
    "Uncontrollable failure part"??? 90% wrong. It is controllable.
    It also works off pressure, which you were not getting, causing the coolant to overflow.
    Since there is less pressure on the impeller, it will spin faster, and faster.
    There needs to have the back pressure to push through.

    And when it got low, coolant wasn't flowing causing the engine to over heat.
    Which is very possible to have caused more damage, head gasket, warped head, scored
    cylinder walls, etc......
    Since you had NO problem before the work, it's not likely the coolant pump just failed.

    Any other engine damage will depend on how soon you turned the car off when the light came on.
    How many miles you have on it is minor.

    You final decision on what you pay, is up to you.
    I personally would never go back to this person. What will he tell you next time to get money
    out of you to make up for the money he didn't get???? How much extra labor cost will he charge?
    How much extra will he raise the cost of a part?????

     
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  11. CA2012PriusOwner

    CA2012PriusOwner New Member

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    The Saga Continues... (I feel sick!)

    Today I went to pick up the car and paid him $419 for the parts (water pump, thermostat, coolant?).

    I started the car and headed home.

    Within a few thousand feet, a warning triangle light /!\ comes on and a message says "Check Hybrid System - Stop the Vehicle in a Safe Place."

    Now it's back at his shop and I'm waiting to hear what he says is going on and why.
     
  12. Brian1954

    Brian1954 Active Member

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    Ask for the trouble codes and then post them here.
     
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  13. V Sport Wagon

    V Sport Wagon Member

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    Always change water pump, thermostat every 100k no matter what. With a stuck pump, it is almost for sure there's some head gasket damage. At 200k, I would save money for some big repairs in your near future.
     
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  14. ASRDogman

    ASRDogman Senior Member

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    The water pumps are as fragile as some seem to make them out to be.
    Mine was at 267,000 when I was going to change the empeller, but it was fine.
    Until I dropped it as I was putting it back in, and broke the plastic. So I installed the
    new one I had.
    But if the engine has over heated. It would probably be a good idea to replace the empeller.
    That's the weekest part of the pump, because it's plastic. And the white parts seems to slit.
     
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  15. CA2012PriusOwner

    CA2012PriusOwner New Member

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    Warning triangle light /!\ is on with the message: "Check Hybrid System - Stop the Vehicle in a Safe Place."

    Trouble codes:

    P0AA6-526
    P0AA6-614


     
  16. Tombukt2

    Tombukt2 Senior Member

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    Yeah your HV battery is an isolated and it's pointing to the inverter area I think I have to look at the chart again.
     
  17. Brian1954

    Brian1954 Active Member

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    This may help you with the P0AA6-614 trouble code. The diagram below is for a Gen 2 Prius, but I believe the Gen 3 Prius is the same for the location of the 614 INF code. @ChapmanF can correct me if I am wrong.

     
    #17 Brian1954, Feb 9, 2024
    Last edited: Feb 9, 2024
  18. ChapmanF

    ChapmanF Senior Member

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    Mostly the same. One change in Gen 3 is that the A/C inverter circuitry moved from inside the inverter box to inside the A/C compressor itself. That means in Gen 3 the 611 area has shrunk to include only the compressor's own innards, and the 614 area has grown to also include the orange wires going to the compressor.
     
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