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Head gasket blown after catalytic converter repair?

Discussion in 'Gen 3 Prius Technical Discussion' started by Brittany Blackwell, Jun 9, 2022.

  1. Brittany Blackwell

    Brittany Blackwell New Member

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    Greetings wise folks of Priuschat,
    My 2013 has 178k miles on it. 6 weeks ago my catalytic converter was stolen over night. I took it to Toyota and it sat for 6 weeks while we waited on the cat to come in. Went down yesterday to pick it up, and as soon as I turned it on the check engine like was on. They scanned for codes and said misfire on cylinder 2 and 3. Left the car there for the mechanic to investigate further. They called me today saying that the head gasket was blown and needed to be replaced.

    I’m not very mechanically inclined, I do change my own oil on time and check in between changes to make sure it’s not getting low. Other than that I rely on the dealership to do the correct maintenance on it. I’m just wondering if this timeline makes sense? The engine light was NOT on before the cat theft and there was absolutely no indication of head gasket issues. I understand that it’s an issue and I’m at the right mileage for this to happen, but there were no problems at all until after it has been with them for 6 weeks. Is this strange?
     
  2. PriusCamper

    PriusCamper Senior Member

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    While it's always tempting to be suspicious, as a mechanic who is often on the other side of this... Sometimes coincidences are nothing more than coincidences. But, just in case, if you can avoid giving that shop any more of your money and have someone else do the work that'd be wise.

    Also in general a failed head gasket diagnosis on a Gen3 Prius doesn't mean you instantly have to fix it. As long as the engine isn't running rough on start up and your coolant reservoir isn't going down very fast you can use the car for short trips around town, sometimes for years without much of an issue. Just don't push it too far because once the engine starts running rough you can ruin the dampener inside the transmission and that will get super expensive.
     
    2010moneypit? likes this.
  3. rjparker

    rjparker Tu Humilde Sirviente

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    I doubt there is anything the mechanic or anyone could have done to create a hg problem.

    I would get the car back and check the symptoms. As suggested, it may run fine for awhile or it may be time for a hg or engine. The risk is a smaller hg job could progress to an engine. Either way, shop around for an independent shop.

    If it is a head gasket, odds are it was leaking an occasional small amount of coolant and sealing itself off everytime you started it. Normally this creates no codes but could have had a random start up rattle. But sitting for six weeks under the right conditions could aggravate a small leak enough to create a full blown hg leak that will create codes.

    Or it could have been fouled plugs due to the gen3 liquids in the intake problem or several other reasons. Driving it yourself might tell the story.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    178K miles. And presumably the EGR circuit (including intake manifold never cleaned)? You've done better than some to dodge head gasket failure this long. And Toyota's done squat, basically.
     
  5. PriusCamper

    PriusCamper Senior Member

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    Makes me think the root of Toyota's denial is based on as long as the car gets at least 100K miles before headgasket blows, it's not their problem.
     
    Mendel Leisk likes this.
  6. Tombukt2

    Tombukt2 Senior Member

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    I guess this is a carb certified car and one of those funny States is why it went to the dealer for the converter I wouldn't have to do that here so makes a humongous difference you know $1,300 part versus $140