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Oil consumption/leak on 2011 prius with 160k miles

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Bridger, May 13, 2024.

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  1. Bridger

    Bridger Junior Member

    Joined:
    Nov 18, 2021
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    Location:
    Montana
    Vehicle:
    2011 Prius
    Model:
    One
    To start off, I've known this car had oil issues. I shouldn't have bought it, but I did. I've put 40k miles on it and have to keep a regular eye on oil levels. I figured it was burning it, cause that's what people say Prius do. Oil consumption has been pretty steady at what seems a severe 1qt/500 miles. Only recently did I consider it to be leaking more than it's burning. The tire shop, after inspection told me it's leaking from the head gasket, timing cover and split case. Let's keep in mind that this info is from a tire shop that then told me I'd have to take the car elsewhere to have the work done. I'm not going to spend $3500 to have a shop replace my head gasket, but have watched a few videos and feel interested in giving it a shot myself. My question is, do I trust that a head gasket will fix the problem? It looks like I will do the timing cover in the process and I've done little research on the splitcase to see about resealing that.

    I don't have a lift or an engine hoist to really get in and look at things. How likely is it that the tire shop got it right in their estimations of where my leaks are coming from.

    A few notes, I have no mixing of oil and coolant, no loss of coolant, no oil puddle under car, no oil splattered up the back side, but the foam insulation in my under engine shield is fairly saturated and I can see oil down the backside of the engine. I've cleaned the EGR system and replaced PCV. How much of my oil loss is really caused by the leaks then, and how much is it burning. Any and all advice is appreciated. Thanks!
     
    #1 Bridger, May 13, 2024
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
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    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Leak down testing and things like that these chemical tests will give you an idea whether you have any leaking in what have you going on pretty quickly this is common in this model seemingly but probably not in the grand scheme of things I guess Just try not to get too much in over your head You may not have a head gasket leak as of yet. You can borrow a boroscope and have a look especially between 1:00 and 2:00 look back up at the head gasket surface from inside the bore and if you see droplets those will be water droplets but usually when the fire's getting put out by water the engine becomes unbalanced and this horrid rattling goes on and you won't forget it It initially may start at first start in the morning. You can stave off a few weeks by loosening the cap to the degas bottle. But all in all don't get in over your head I mean unless the car is really pristine inside and pretty much out It's just not worth the trouble generally maybe it'll be a labor of love who knows.
     
    #2 Tombukt2, May 13, 2024
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    When head gaskets leak on 3rd gen it's typically been coolant leaking into combustion chambers.

    With a 2011, you have the "low tension" piston rings (they have less outward springiness). Presumably in response to excessive oil consumption reports, Toyota finnally revised the rings (and pistons to accommodate the revised rings), sometime through model year 2014.

    You "may" also have a leaking head gasket, or soon, due to EGR components (including EGR passages in intake manifold) clogging with carbon, and the consequence being combustion chambers having more oxygen (less exhaust gas in the mix), and usually unevenly so, with cylinder one experiencing this earlier.

    The Toyota proscribed fix for the oil consumption is outlined in the two attachments, involves changing the ring/pistons (a tacit admission that they're responsible for the excessive oil consumption). For a DIY'r, not wanting to swap pistons and rings: for around two grand USD you can get a new short block, which will have the revised pistons and rings. With new head bolts and a gasket kit (includes head gasket) you will have a restored engine, if the machined surfaces between head and block have not distorted.

    More info in the attached Toyota TSB's.
     

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    #3 Mendel Leisk, May 13, 2024
    Last edited: May 13, 2024
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