Flushing Cooling System After Using Head Gasket Sealer?

Discussion in 'Prius v Technical Discussion' started by DaveCo, Jul 13, 2023.

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  1. DaveCo

    DaveCo Junior Member

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    I bought a 2013 Prius V (207### miles) from a dealer in another town (3 hours away) for cheap, relatively speaking. I was told by the dealer that it was in good mechanical condition and I've been crossing my fingers hoping he was telling me the truth. Unfortunately, a few days later there was a cold start rattle (not super strong) and after I plugged my wireless OBD2 reader, I got codes P0300, P0301 and P0302 for multiple misfires (cyls 1 and 2) which is a symptom of a bad head gasket. I hadn't gotten these codes when checked out the car for the first time. I'm taking it to a local Toyota dealer for them to do a multipoint inspection and do a more accurate diagnosis of the issue.
    If it's a head gasket, I plan on doing it. I've already done a couple of Prius head gaskets before. However, I'm afraid that someone previously put a head gasket sealer in the cooling system as I know that that has the potential of damaging the water pump, thermostat, radiator and heater core (other things too?). I know this first hand as the last car I fixed needed a new thermostat and water pump due to sediments solidified on them (the water pump got completely stuck).
    If a gasket sealer was used, is there a way to flush the system such that the gasket sealer is washed from all the parts that interact with the coolant?
    Thanks!
     
    #1 DaveCo, Jul 13, 2023
  2. rjparker

    rjparker Tu Humilde Sirviente

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    I would do multiple flushes with a heat cycle each time. Use distilled water. You will not get much more than a gallon each time so the goal is to dilute. Use the Toyota concentrated coolant for the final refill after carefully calculating the water still in the system.

    Too often diy hg on these engines have to be repeated, sometimes eventually replacing the engine. Many dealers won't do a hg alone for these reasons.

    A head gasket at a dealer who will do it will cost as much as a smart guy can get a well rebuilt engine installed elsewhere. Then you get new piston and rings and a remanufactured head as well as assurance you don't have oil leaks. The rings are a factory flaw and the only hg contributor acknowledged by Toyota, regardless of the egr boys around here. Everything will be carbon up so a good clean of the egr is recommended as part of any repair. A new intake manifold is recommended as well.
     
    #2 rjparker, Jul 14, 2023
    Last edited: Jul 14, 2023
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    A Toyota dealership? How good of a deal? Would you have bought it if you knew what you know now?

    what’s the “cooling off period laws” where you are? Ask for a refund; citing misrepresentation?

    funny thing is, most any 3rd gen used Prius for sale is likely to be “misrepresented”; it’s the “Toyota screwed the pooch” gen.
     
    #3 Mendel Leisk, Jul 14, 2023
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  4. DaveCo

    DaveCo Junior Member

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    Thanks for your responses.

    It wasn't a Toyota dealer who sold me the car, it was a random dealer who sold on Facebook in another town three hours away. I am planning though to take the car to a local Toyota dealer just for diagnosis. At this point, the car is not losing coolant. At least not noticeably.

    I knew that I was taking a risk when buying this Prius V, but we really needed something with a lot more space than a regular Prius. If I had been told the car had a gasket leak, I would have negotiated for an even lower price and fixed it myself. I have already bought a 2011 Prius SE with a blown head gasket once, fixed it, and is now my daily driver. I've already put 20k miles on it since I fixed it this time last year, and it's been just as reliable as any non-hybrid Toyota that I have ever owned. But this one hadn't been treated with a gasket sealer for the radiator.
     
    #4 DaveCo, Jul 14, 2023
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  5. Air_Boss

    Air_Boss Senior Member

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    Did a one-and- done sealer fix on a leaky V6 rear cylinder bank HG on three year old 1996 Dodge Grand Caravan with 36,000 miles, just out of warranty, and it held through 110,000 miles when it was stolen.
     
    #5 Air_Boss, Jul 15, 2023
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Just to point it out- you can get a quality aftermarket replacement radiator for these cars for not much over $100. That's a lot of peace-of-mind per Benjamin in my book.
     
    #6 Leadfoot J. McCoalroller, Jul 15, 2023
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  7. Tim Jones

    Tim Jones Senior Member

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    #7 Tim Jones, Jul 18, 2023
  8. DaveCo

    DaveCo Junior Member

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    This is a good point. I can get a Denso radiator for for $100 from RockAuto.
     
    #8 DaveCo, Jul 27, 2023
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  9. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Even better! I hadn't spotted that.

    You'll still want to flush everyting, and I think Mendel has a vinegar recipe that is supposed to help. There are other places where these systems can clog and cause you real trouble, so anything you can do to clean it out is great.

    I think starting over with a new radiator is a good step.
     
    #9 Leadfoot J. McCoalroller, Jul 27, 2023
  10. Tim Jones

    Tim Jones Senior Member

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    Thermostat
     
    #10 Tim Jones, Jul 28, 2023
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    See “flushing out…” in my signature.
     
    #11 Mendel Leisk, Jul 28, 2023
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