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2010 prius head gasket blown vs crack

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Natexan, Nov 10, 2020.

  1. Natexan

    Natexan New Member

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    Hey all, I bought a 2010 prius II with 155k miles, burning coolant/ running rough from a soccer mom for a few hundred bucks. She said the valve cover gasket got blown out and replaced, new ignition coils, new spark plugs, new battery, new egr, . They then said it was burning coolant and has a crack or blown head gasket and she decided to sell and buy a new car for her daughter (was her daughters). It has the codes (U0100, P0300, P0303, P0304, P0117, P3190) Body/interior/bay is super clean, clean title. I contacted the mechanic and they said it was a solid car except for whatever is going on with the coolant. I expected to replace the engine with a jdm engine but if I can confidently get away with a head gasket change I would prefer that. I saw some people have problems with jdm engines, does anyone know anything about that? Also I saw about using a 2016 engine instead but I dont like modifying things if I dont have to (unless its totally worth it). Anybody have the best path for me to recommend?
     
  2. scona

    scona Active Member

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    Sell it to a soccer mom for a couple of hundred bucks.....
     
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  3. Natexan

    Natexan New Member

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    I actually looked forward to working on this, more curious what my best path of repair is?
     
  4. Gliderguy

    Gliderguy Junior Member

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    I did a head gasket on mine at 168,000 I now have 195,000. A cracked block is not impossible, but pretty rare. What DOES happen is if enough coolant is put into the leaking cylinder (the blow-by pressurizes the cooling system to maximum, then when you park it squirts backwards into the cylinder). If enough coolant gets into the cylinder, when it goes to start it hydrolocks and bends the connecting rod. If you have a bent rod it might be better to start from scratch, but if you can verify that all the pistons come up to exactly the same height, replacing the head gasket is not out of reach. A fast mechanic might be able to do it in a very long day, many people could do it in a weekend, but I am fat and slow and it took me two weekends. one for teardown (and then to go and mill the head flat) and another for assembly. Lanmeister just went down the same road, and his vehicle had a few other issues, but he finally got it running good with about a total investment of 3000 (including purchasing the car)

    If you are trying to use the car at all as-is release the pressure on the cooling system by carefully venting it off each time you shut down. It is also possible to leave the radiator overflow tank cap loose to accomplish the same thing, this may save you from a bent connecting rod, if it is not already bent.

    If the battery is good you can re-coup your few hundred bucks just by selling those modules if you find the engine repair a lost cause at any point.
     
  5. Natexan

    Natexan New Member

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    how could i check to make sure none of the rods are bent?
     
  6. ASRDogman

    ASRDogman Senior Member

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    If the head is still attached, you can remove the spark plugs, and use a screw driver or
    some type of a rod to insert in the spark plug hole, rotate the engine and get the piston
    at the highest spot, mark the stick, then do the same for the other 3.
    They should all be the same, probably within a millimeter or so, max.

    If the head is off, rotate until two pistons are at the top, then the same for the other two.
    All 4 should be at the same height. It not, likely a rod is bent...

     
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  7. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Tough call, but if I woke up with this car in MY driveway and it's as reported (above average condition, new ignition coils, new spark plugs, new [aux] battery, new egr) then I would verify that the bottom end is straight and repair the motor.

    The difference between THIS post and the other 90-percent, where I would recommend a motorectomy, is that YOU would be doing the labor and since the car was already an inanimate object when you bought it, you're not thumbing rides until it gets fixed.
    You only have a few hundred bucks in the car thus far, so your exposure on this project will be limited to some time and maybe a few hundred more bucks in parts and other expenses.

    .....besides.
    More lock-downs are coming.
    you have to do SOMETHING with all that free time, right?
     
    #7 ETC(SS), Nov 11, 2020
    Last edited: Nov 11, 2020
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  8. Grit

    Grit Senior Member

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    :whistle:
     
  9. Natexan

    Natexan New Member

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    great idea, thanks!
     
  10. ASRDogman

    ASRDogman Senior Member

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    You're welcome. And you can do pistons 1 and 3, then 2 and 4.

     
  11. Natexan

    Natexan New Member

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    Just got back and listened to it. (seller started it before buying, had a lot of white smoke, misfiring or something, noisy, rough) It actually started smoothly and ran smoothly for a bit, I then heard a noise that came and went and tried to trace it and seemed like near the transmission area or lower end then the car shut itself off suddenly. (not sure what that means on the priuses?) Going to check for bent rods through the plug port next probably. Yea totally I actually look forward to work on it, i just want to make sure i am going in the right direction. Just rebuilt a 3rd gen 4runner so thats my DD. Perfect lockdown project.
     
    #11 Natexan, Nov 11, 2020
    Last edited: Nov 11, 2020
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  12. KaseyMcc

    KaseyMcc Junior Member

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    Please correct me if I'm wrong, but when piston 1 is at the top of it's stroke, wouldn't 4 also be at the top of it's stroke? and when 2 is at it's top, 3 would also be at the top? I'm afraid I might have a bent 4th rod, so getting this info settled would be really helpful.
     
  13. ChapmanF

    ChapmanF Senior Member

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    Exactly: for balance, the two outermost pistons, 1 and 4, move together, and the two inner, 2 and 3, are down when 1 and 4 are up, and vice versa.
     
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  14. KaseyMcc

    KaseyMcc Junior Member

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    Thanks so much for verifying Chap! I'm gonna confirm when I get home this evening, but pretty sure I've got a bent 4th connecting rod. I was just gonna be doing a HG replacement but now it seems like I might be pulling the damn engine.
     
  15. Ben Je

    Ben Je Junior Member

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    So to be clear, wherever the crank is positioned, 1 and 4 should be the same height, same for 2 and 3? I'm about to do a HG replacement and want to make sure I don't have a bent rod. First post!
     
  16. ChapmanF

    ChapmanF Senior Member

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  17. Ben Je

    Ben Je Junior Member

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    Thank you, I just checked and no evidence of a bent rod. On with the HG.