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Rough Startup cured. Blown Head Gasket.

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by GeorgeO, Jan 8, 2019.

  1. GeorgeO

    GeorgeO New Member

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    First time posting.
    Like many people, My 2012 Prius V had the rough startup issue, from about 10,000 miles. It happened about once a week and lasted for 20 seconds or so. Pulling the plug wires, verified that it was always cylinder one. Well, one week, it happened everyday and then I noticed white smoke poring out of the exhaust. This was at 185,000 miles.

    I assumed that I blew a head gasket. Pulling the coolant cap confirmed my fears, as air came rushing out. I'm pretty mechanically inclined, but I enlisted the help of a good friend and serious mechanic. It took about 28 man hours to complete the whole job. Don't forget to pull the oil pan and clean the bottom of the motor.

    With the tear down, I discovered that the head gasket was missing material on cylinder one. It is my belief that the gasket was faulty from the factory.This caused a temporary fouled plug state. I have put 10,000 miles on it, since the new head gasket went on, and it has not had a single rough start. I had six years of rough starts, until I replaced the gasket.

    If you look at the pictures, you will see the small amount of missing material, near cylinder one.

    On a positive note, These engines are pretty easy to work on. There are no belts or belt accessories to worry about. Prius1.jpg Prius2.jpg Prius3.jpg prius4.jpg Prius1.jpg Prius2.jpg Prius3.jpg prius4.jpg prius5.jpg prius6.jpg
     
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  2. Air_Boss

    Air_Boss Senior Member

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    Gasket sealant more likely eroded, but that would still mean a faulty bond from the factory.

    In any case, glad you got it sorted out and thanks for the tips on head removal.

    If I may ask, there appears to be a lot of corrosion in the engine compartment, ancillaries, etc.

    Is this environmental, where you are located?
     
    #2 Air_Boss, Jan 8, 2019
    Last edited: Jan 8, 2019
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  3. rjparker

    rjparker Tu Humilde Sirviente

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    Very interesting. So was the head gasket actually gone at that spot or was it just a coating missing?
    Roughly how much did the parts cost?
    head gasket.jpg
     
    #3 rjparker, Jan 8, 2019
    Last edited: Jan 8, 2019
  4. bisco

    bisco cookie crumbler

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    how does the cost compare to putting in a low mile engine?
     
  5. JC91006

    JC91006 Senior Member

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    Do you have a picture of the intake ports before you covered them with blue tape? I'm curious if it's all gunked up.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I was noticing that too. He has a "tricky" location: a US zip code, just north of Chicago. I'm guessing brutal winters, lots of road salt/sand, and parking outside?

    @GeorgeO if you haven't got to it, clean the EGR circuit, stem-to-stern. An Oil Catch Can install is good too. I'd assume you cleaned out the intake manifold, having it off. You want to pay special attention to the EGR passages, one per port.

    For clarification (head gasket in pic is flipped and rotated 180 deg), I believe this is the point where the head gasket failed:

    upload_2019-1-8_12-8-33.png
     
    #6 Mendel Leisk, Jan 8, 2019
    Last edited: Jan 8, 2019
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  7. GeorgeO

    GeorgeO New Member

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    The corrosion is from 185,000 miles in Northern Illinois salt.
     
  8. GeorgeO

    GeorgeO New Member

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    Just the coating was missing.
     
  9. GeorgeO

    GeorgeO New Member

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    Total parts (gasket set, rtv, coolant, two oil changes, new head bolts) came to less than $400. I will say, that the cylinder walls and pistons looked great, even after 185,000 miles.
     
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  10. GeorgeO

    GeorgeO New Member

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    I do not have a picture of the intake ports, but they were clean. Also, I put the tape on, before I realized it was a two piece head. I've pulled a few Jeep heads before, but they were all one piece.
     
    #10 GeorgeO, Jan 8, 2019
    Last edited: Jan 8, 2019
  11. GeorgeO

    GeorgeO New Member

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    You guessed the conditions correctly. Brutal winters, salt, and even a long gravel driveway. Not to forget, a daily three hour commute.

    You guessed the correct area of the failure too.

    Surprisingly, the whole EGR system was pretty clean.
     
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  12. Mendel Leisk

    Mendel Leisk Senior Member

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    Three hours in total, or both ways?
     
  13. GeorgeO

    GeorgeO New Member

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    total
     
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  14. Cmmasterjohn

    Cmmasterjohn New Member

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    Did you replace the head bolts or reuse? I am preparing to replace the head gasket as well.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Have a look at the attached TSB's. The second one documents a piston/ring replacement, including pretty much complete gasket replacement as well (including head gasket). There is a gasket kit part number indicated, btw.

    Replacement cylinder head bolts are not included in a first list, which I guess is the essential parts only. But they are noted (and there's a revised parts number) in a second list, indicated "as needed". All the parts numbers are there, which would make it easy to price. I guess if in doubt, if the head bolts are not that pricey, just replace. The torque instruction is pretty tough on them: torque to a spec, and then turn a further 90 degrees. They take a special socket too.

    Note too, the TSB has a lot of references to the Toyota Repair Manual, doesn't go into complete detail in the TSB, on some of the removal steps. Judging from the parts list, I think they're expecting the entire engine/transaxle to be pulled as an assembly. If you're separating the the transaxle, just pulling the engine. Then there's a number of parts in the first part list that aren't needed, the large castle nut that goes on the end of the driveshaft for example.

    I've also attached a few relevant Repair Manual excerpts; if you can think of more just ask.
     

    Attached Files:

    #15 Mendel Leisk, Jan 20, 2019
    Last edited: Jan 20, 2019
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  16. rjparker

    rjparker Tu Humilde Sirviente

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    So are they saying Toyota's repair manual for a head gasket says pull the engine? If so, that sounds like a bit much unless you have a lift and plenty of customer cash to do it. When I replaced by antenna base preamp under the rear portion of the headliner, the manual said pull the windshield and everything attached to it so that the headliner could be removed through the windshield opening. Just to access one antenna base nut. Sometimes I think they simply reverse the steps they took when building the car.
     
  17. Mendel Leisk

    Mendel Leisk Senior Member

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    No, the instruction is primarily piston/ring replacement. Head gasket (and pretty all other gaskets) are replaced as a matter of course.

    OTOH: the timing chain cover has to come off I believe, to remove the cylinder head. And installing that properly is such a royal pain, it might be best to pull the engine.

    Full disclosure: I've never done any of these procedures, lol.
     
  18. Mendel Leisk

    Mendel Leisk Senior Member

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    This video is very good, mentioned in another thread (which I can't find now lol). Head gasket replacement without pulling the engine. Lots of good tips:

     
  19. GeorgeO

    GeorgeO New Member

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    I used new head bolts. They are cheep. Remember to follow the proper torque sequence.
     
  20. Mendel Leisk

    Mendel Leisk Senior Member

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    #20 Mendel Leisk, Jan 24, 2019
    Last edited: Jan 24, 2019