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how to best start prius with bad headgasket?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by waldox, Apr 30, 2022.

  1. waldox

    waldox Junior Member

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    i have a 2010 prius with a bad head gasket
    due to the shortage of parts and a long wait 4 weeks for the new piston rings and head gasket
    i need to use the car once a week to keep 12v charged, run errands and empty out the engine of coolant.
    what is the best way to start the car so it is least likely to hydro lock and blow the engine on startup?
    ie remove fuse for fuel injector or spark plugs temporarily?
    any ideas?
    thanks
     
    #1 waldox, Apr 30, 2022
    Last edited: Apr 30, 2022
  2. bisco

    bisco cookie crumbler

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    have you cleaned out the egr circuit?

    you can disconnect the 12v and not worry about it. is there any other way to run errands?
     
    #2 bisco, Apr 30, 2022
  3. waldox

    waldox Junior Member

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    yes done the egr cooler and intake manifold cleaning, need to use it once in a while even minimally for errands
     
    #3 waldox, Apr 30, 2022
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  4. bisco

    bisco cookie crumbler

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    i think i would just start it. how bad is the hg now, is it over heating?
     
    #4 bisco, Apr 30, 2022
  5. waldox

    waldox Junior Member

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    get the usual vibrations/missfire and loss of coolant on startup car is at 211k miles, i know the engine can blow anytime while waiting for the head gasket replacement from mechanic but parts are backordered 4 weeks.... ahhh
     
    #5 waldox, Apr 30, 2022
  6. bisco

    bisco cookie crumbler

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    i suppose the problem is high revving warm up cycle, but i suspect that is a software thing
     
    #6 bisco, Apr 30, 2022
  7. waldox

    waldox Junior Member

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    im thinking the coolant pooled up in the combustion chamber on startup, then the strong electric motor (starter) pushes up the pistons with coolant and breaks the engine. this is likely what breaks the engine with bad head gaskets.
     
    #7 waldox, Apr 30, 2022
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  8. ASRDogman

    ASRDogman Senior Member

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    The only SAFE way is to remove the plugs....
    When it cranks over, the pistons will blow out all the coolant.

    It will be a royal pain to remove the coils and plugs all the time.

    It would be easier to remove the coolant tank cap, SLOWLY to bleed off the pressure.
    Hopefully, you'll only get a little coolant in the cylinder.

    BEST thing is to NOT drive it. Maybe rent a car??? You're risking bending a connecting rod,
    or having it shoot through the crank case...

     
    #8 ASRDogman, Apr 30, 2022
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  9. jerrymildred

    jerrymildred Senior Member

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    All I can think of is pulling the spark plugs and crank it before every start. Shouldn't take more than a couple hours to remove the wipers, wiper motors, cowling, coils, and plugs, blow out the cylinders, and reassemble it all.

    Otherwise, you either risk a bent or broken connection rod every time, or you park it, put a battery charger on the 12V, and call Uber or rent something.

    I can't think of any other options.
     
    #9 jerrymildred, Apr 30, 2022
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  10. CR94

    CR94 Senior Member

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    How about turning the crankshaft over at least two revolution by hand with a wrench before starting? That would take a lot less time than removing and replacing the spark plugs. Is no other vehicle available for errands, not even a bicycle?
     
    #10 CR94, Apr 30, 2022
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  11. waldox

    waldox Junior Member

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    good ideas guys...not wanting to do a 2 hour job pulling plugs everytime i run a 15 min errand LOL

    good idea cranking the engine. its parked along the sidewalk and have limited access under the car. do you have a link or a post on how to hand crank the engine quickly without disassembling major parts?
     
    #11 waldox, Apr 30, 2022
  12. CR94

    CR94 Senior Member

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    ½" ratchet with appropriate socket on the center of the pulley. You can reach it without disassembling anything. Easy!

    Disclaimer: I'm not claiming that technique would totally eliminate the risk of buckling a rod if you have a head-gasket leak, only that it might reduce it.
     
    #12 CR94, May 1, 2022
  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Or:

    1. Put the 12 volt on a charger.
    2. Take a long look at those errands. If it’s grocery shopping, is there anywhere closer, or change the menu, or. If it’s just a few blocks…? If you’re in an off-in-the-boonies location I appreciate these ideas may be non-starters, but just in case.
    3. Rent a car?
     
    #13 Mendel Leisk, May 1, 2022
  14. nicoj36

    nicoj36 Active Member

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    Try this

     
    #14 nicoj36, May 3, 2022
  15. waldox

    waldox Junior Member

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    ok will try that with 1/2" socket, right now car is down a few weeks while i condition the hybrid battery during the wait. hybrid pack is showing 40% :( but no codes yet
     
    #15 waldox, May 4, 2022
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