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Engine knock + white/blue exhaust = replace engine?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by LHR, Dec 12, 2021.

  1. LHR

    LHR Junior Member

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    Hi folks,

    I have a 2012 Prius 3 with 246k miles. More than a year ago it started knocking and shuddering for <5 sec. on startup, usually when cold. I got "Misfire detected in cylinder 2."

    I researched the problem on these forums and then added a bottle of stop-leak to the coolant, ran it for 15 minutes, and then replaced the coolant with clean. I also replaced the spark plugs, swapped the #2 and #3 coils, cleaned the EGR tube and intake manifold, and replaced the EGR valve.

    Now it's doing it again, and I noticed blue-white exhaust just after startup. No codes, though.

    1. Is this pretty conclusive that it's the head gasket? (And so the TSB about the intake manifold is irrelevant.)

    2. Can you point me to any good summary and advice about choosing a used or rebuilt engine, if that's the best option?

    3. When I was reading the forums a couple years ago, I thought I read that the 2013 was redesigned to avoid this problem, but now I can't find that. Is that correct?

    Thanks!


    Luke
     
    #1 LHR, Dec 12, 2021
  2. bisco

    bisco cookie crumbler

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    iirc, 2014 got a partial fix, and 15 got a full. but we really don't know if they soved the problem, as those cars are not old enough yet.
    a leak down test would confirm your diagnosis
     
    #2 bisco, Dec 12, 2021
  3. jzchen

    jzchen Newbie!

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    Usually the stop leak products have some sort of warranty. I would shoot an email to the manufacturer for advice...

    REVVL V+ 5G ?
     
    #3 jzchen, Dec 13, 2021
  4. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Part way through 2014 there was a complete fix (revised pistons/rings) for an unrelated issue, the oil consumption. It was in 2012 model year (I think), Toyota came up with a bandage solution for the EGR clogging, a revised intake manifold and EGR valve, but I don't think it did squat.

    Yes, that's best method.

    If your oil consumption is not much, head gasket replacement would be cheapest, if you DIY. If going with pros, and/or the oil consumption is getting up there, then swapping in a salvage engine is probably best.
     
    #4 Mendel Leisk, Dec 13, 2021
  5. rjparker

    rjparker Tu Humilde Sirviente

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    A rebuilt engine is the best solution. Minimum new rings, machined head, new seals. Cleaned egr system. Oil consumption is most likely the issue but the revised gen4 engine improved thermal management of the cylinders and provided a rerouted and larger egr system. Also Toyota revised coolant passages in the 2016 and above gen4 models (except the v wagon which remained gen3).

    Did 4th Gen fix 3rd Gen? | PriusChat
     
    #5 rjparker, Dec 13, 2021
    Last edited: Dec 13, 2021
    ammdb likes this.
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