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Excessive Oil Consumption

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Christian_cool, Feb 1, 2016.

  1. Christian_cool

    Christian_cool Junior Member

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    183.000km - 2010 Prius.
    Hello Prius Friends. As for a long time i have noticed my prius eat up my oil in a faster rate than before. I see many ppl. complaining about this. With so many reasons it could be am confused what it could be. And since i dont trust my rip-off dealer, i am asking here :)
    How can i find out the problem?
    What happens if i run the engine without oil?

    thanks
     
  2. bisco

    bisco cookie crumbler

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    you would have to replace the engine. the best thing to do is start checking it everyday, then slowly space out the checking to 2 days, 3 days, and etc. until you're comfortable with an interval where you would add a half quart of oil at a time, or something reasonable like that.
    you don't want it to get down to the min level on the dipstick, so best to start at max and replenish frequently.
    have you tracked usage yet?
     
  3. FuelMiser

    FuelMiser Senior Member

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    There's nothing you can do about it now. Just be vigilant about monitoring. Perhaps at every fill-up. There's probably a major warning if the car detects too low oil level (or oil pressure?) You would not want to continue driving in this condition or face serious engine damage.
     
  4. David Beale

    David Beale Senior Member

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    There are several theories as to why the engine begins to use oil.
    -I- think it's because of the 0W20 oil, used for fuel economy. It's so thin I don't think the oil ring can clean enough of it off the cylinder walls. This will cause carboning of the rings, making the situation worse. I think this also causes the EGR system to plug up.
    But it could be something much more technical. What do I know? ;)
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Christian, knowing the history on your car, the troubles with EGR clogging, maybe some connection?

    183,000 is starting to get up there. Per bisco, do you have a sense of how fast it's consuming oil?
     
  6. CR94

    CR94 Senior Member

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    How can that theory account for the fact that the engines generally don't consume much oil when new?
     
  7. Former Member 68813

    Former Member 68813 Senior Member

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    well, the theory is wrong. it's well known that lower viscosity oil makes thinner film of oil and circulates better in the oil ring grove.
     
  8. CR94

    CR94 Senior Member

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    My point exactly. Evidently not even 0W-20 circulates well enough, or the piston simply gets too hot.
     
  9. David Beale

    David Beale Senior Member

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    The high consumption only starts after the rings become clogged with carbon. The small loss caused by incomplete removal by the oil ring is not noticeable.

    If you guys are so sure how about a tear-down to inspect the oil ring? It's not hard to remove one piston. ;)
     
  10. Former Member 68813

    Former Member 68813 Senior Member

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    of course everyone can agree with this one.

    please provide the evidence that low viscosity oil leads to "incomplete removal." tribology textbooks clearly state that oil film thickness is correlated with viscosity.

    the tear down pictures are freely available on the net and even this forum.
     
    kenichols29 likes this.
  11. ETP

    ETP 2021 Prime(Limit),Highlander HYB Plat,B52-D,G,F,H

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    Compression check is due after you check the PCV and EGR valves. If you go to a 0w40 or 5w30 and the oil consumption deceases then you have a clue. Normally the valve seals go first but it could be rings. Also is your oil clean? No water in it? Does it make noise? Is the noise temperature related?
    Also make sure your air flow is unrestricted to your intake.

    Seems most folks are getting more miles than that before an engine R&R.
     
  12. Former Member 68813

    Former Member 68813 Senior Member

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    no, compression is not effected by oil control ring problems. as you probably should know, there is a set of 3 rings per cylinder. one of them is called compression ring, and it's not the oil ring.

    in toyotas valve seals don't go first, it's usually gummed up oil control rings.
     
    #12 Former Member 68813, Feb 5, 2016
    Last edited: Feb 5, 2016
    m.wynn likes this.
  13. farmecologist

    farmecologist Senior Member

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    Unfortunately, discussing this is another "it's like discussing religion" debate....you will most likely never get a clear answer.

    That being said, I noticed that our 2010 is using some oil..but not excessive.
     
  14. bisco

    bisco cookie crumbler

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    and not only that, the trail of evidence seems to lead to nowhere.

    of course, it would be cool if christian responded to our reply's.
     
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  15. Former Member 68813

    Former Member 68813 Senior Member

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    not really. what is the part you don't understand?