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2016 Possibly blown head gasket

Discussion in 'Gen 4 Prius Main Forum' started by Josh H, Aug 31, 2022.

  1. Josh H

    Josh H New Member

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    My 2016 Prius IV Touring, at 68K miles, starting running rough last week (daily driver for 2+ years and well maintained). I got the Misfire code with a check engine light the next day. I've changed the spark plugs, and noted discoloration on the 1st cylinder (code was for a misfire on first cylinder). I cleared the codes, but they returned the following day. The engine is running more rough, and I noted a lighter color streaked through my oil when I took the cap off to inspect it since I suspected there might be a head gasket problem. I'm not keen on paying to get the gasket replaced, if it will happen again. Anyone have thoughts on what would have caused this?
    20220830_202324[1563].jpg
     
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  2. ToyXW

    ToyXW Active Member

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    Try swapping the #1 and #2 coils to see if the misfire moves to cylinder #2. Blown head gaskets are rare on gen 4s.

    That picture of the underside of your oil cap does not alarm me - it could easily be normal varnish.
     
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  3. bisco

    bisco cookie crumbler

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    any coolant loss?
     
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  4. Josh H

    Josh H New Member

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    Dealership called and said it was the distributor coil for the first cylinder. I sent it to the shop so as to minimize having the warranty voided. I will remember to try the swapping suggested if this happens in the future. The shop recommended cleaning carbon out of various parts as that was likely the source of the coil going bad.

    Thanks for the tip about the oil appearance not being as alarming as I thought it was. Hopefully it is just that varnish suggested. The oil itself did appear normal to the technicians (I asked for an oil change while it was in the shop already).
     
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  5. dacoobob

    dacoobob Member

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    this does not say "head gasket" to me, especially on a 2016. more likely an ignition system problem-- i'd replace your coils and wires too and see if that resolves it before looking at the HG.
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Do you know the code? They can point to specific cylinder(s). If so try post #2 suggestion, swapping coils/plugs between cylinders.
     
  7. CooCooCaChoo

    CooCooCaChoo Senior Member

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    You shouldn't be able to see oil when you take the oil cap off. If you do see oil, there is too much oil in the car because everything is supposed to drain into the pan. There should be nothing under the valve cover where the cap is. What you are probably seeing is varnish which can be various colors, mostly dark though.
     
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  8. jerrymildred

    jerrymildred Senior Member

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    That looks like varnish to me and the light streaks, I would guess, are from the end of the funnel scraping it off. Another symptom of a HG failure on a Prius is usually white smoke from the tailpipe. The HG usually fails between the water jacket and the combustion chamber.

    I also think it would be smart to try swapping around the ignition coils to see if the code moves with the coils.
     
  9. douglasjre

    douglasjre Senior Member

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    How much oil would have to be in the engine to see it poling under the valve cover
     
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  10. CooCooCaChoo

    CooCooCaChoo Senior Member

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    A lot. I've heard/read mechanic horror stories where owners just kept adding oil instead of doing oil changes.
     
  11. douglasjre

    douglasjre Senior Member

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    Some call these sales opportunities
     
  12. N khan

    N khan New Member

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    Hi
    I opened my water pump after many coolant loses and water pump looked orange whT does this mean
    When water pump is orangeish ?
     
  13. Doug McC

    Doug McC Senior Member

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    That means your whole cooling system is rusting due to depletion of the additives because the coolant wasn’t changed when it actually needed to be. My bet is your inverter coolant is in the same condition. From what I see there, you are going to be spending A LOT OF MONEY real fast.

    That is why Toyota says to check the actual condition of the coolants every 6 months.
     
  14. bisco

    bisco cookie crumbler

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    Good news
     
  15. bisco

    bisco cookie crumbler

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    How many miles on her? Have you followed the maintenance schedule?