Leaking oil / possible high pressure in oil pan.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Piotrus Pan, Sep 23, 2020.

  1. Piotrus Pan

    Piotrus Pan Member

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    Hi everyone!
    I keep having this problem since I bought this car.
    Car was used and it had a hole in the noise dampening foam right above the oil refill cork (pics).
    In the back of the engine, next to exhaust there is one, in my case rusted cover closing some outlet. This rusted part has a gasket that keeps leaking.
    Usually the leak happens when the oil is overfilled (toyota dealer did this to me) or I aggressively step on the gas couple of times.
    This time the leak happened after a long trip (2600km). The trip involved high speed, around 180km/h.
    After this trip I saw a tiny leak near the rusted part but the whole oil was gone! Around 4L just gone.
    I didn't see any areas that 4L of oil could have just poured out so I guess it was burned.
    I had compression test done and all is good, unfortunately Toyota in my are is incompetent and they don't care what information the customer gives so they did not investigate the 4L gone.
    I also found something greased up on the top of the engine, I have no idea what it is.

    Any ideas?

    General area of the problem:


    Closeup of the area. Sorry for vertical ...


    Foam 01.jpg Foam 02.jpg greasy part 01.jpg greasy part 02.jpg Keeps leaking.jpg
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    With leaks coming from various places, maybe try replacing the PCV valve? Or at least remove and clean it. If it's clogged could be causing excessive pressure in crankcase.
     
  3. fotomoto

    fotomoto Senior Member

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    IDK but I can say this, a leak of four liters of oil at highway speeds would cause a HUGE mess and at least some smoke/smells at stops. The pics show a small leak that periodic engine cleaning would keep in check.

    I would suspect human error (short fill?) plus oil consumption on the trip.

    How many miles on the vehicle?
     
    #3 fotomoto, Sep 23, 2020
    Last edited: Sep 23, 2020
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  4. ASRDogman

    ASRDogman Senior Member

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    Check the oil pressure switch. Many think the timing cover is leaking. Maybe.
    Oil pressure switch is easy to check, and replace, and cost a lot less. :)

    Driving 180kph/112mph will suck the oil out of almost any car!!!
    Maybe driving 113kmh/70mph would keep the oil IN the engine.

    Just because the car WILL go that fast is not a reason to drive it that fast. It really was not
    designed for those constant speeds.
     
  5. Piotrus Pan

    Piotrus Pan Member

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    That was my suspect too. I would love to buy one and do it myself but I live in Luxembourg, Europe and it's almost impossible for some reason to get this part. I will have to get it from Toyota.
     
  6. Piotrus Pan

    Piotrus Pan Member

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    Car has 221000KM (137000 miles).
    What's "short fill"? I'm not native English so I don't know if I understand it correctly. Is it when you put not enough oil? Because before every bigger trip I check the usual fluids and so on. Oil was at the "top dot".
     
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  7. Piotrus Pan

    Piotrus Pan Member

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    The "oil pressure switch" is the PCV, right? I'm not native English so I need to make sure on some things.
    In regards of speed, the rating on the car is up to 180km/h. I saw on the net people going 210km/h. In my opinion it should not burn oil as it was petrol.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    PCV (Positive Crankcase Ventilation) is on the front side of engine, below intake manifold. You could just remove, clean (say with carbeuretor cleaner) and reinstall it, if replacement is difficult to get. @NutzAboutBolts has a video on this, accessing from below, which avoids needing to remove intake manifold. It's linked in thread pinned at top of this forum.

    You can test its function too: it should be easy to blow air through it in going away from engine direction, but not in reverse direction. Be careful not to inhale fluid when doing this.

    Theoretically you should apply thread sealant to it when reinstalling, but there may be enough residue. It's not critical to do this: with clean threads it might leak a slight amount of oil, but not serious.

    I'm not completely sure but I think the rusty plate you've pictured might be oil pressure sensor plate, or timing chain tensioner. More likely the tensioner.
     
    #8 Mendel Leisk, Sep 23, 2020
    Last edited: Sep 23, 2020
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  9. Piotrus Pan

    Piotrus Pan Member

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    I saw the video that's why I think I can do it myself.
    I got a medium threadlock so I'll reapply.
    We'll see on the weekend.

    I would also like to say thank you!
    Whenever I have a question you always try to help so thank you again.
     
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  10. Piotrus Pan

    Piotrus Pan Member

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    Hi again.
    The rusty plate is in fact the chain tensioner as you said.

    Due to some "miss comunication" the pcv valve was not changed. They checked the chain as I asked and resealed the "rusty plate".
    I am now supposed to drive around, monitor the oil level and go back to Toyota in 1000km.
    After all this oil leak/burn my consumption went up.
    I was getting 4.4L/100km (~53mpg), now it's 5.6L/100km (~42mpg).
    I do have new tires but during my trip, in city I managed to get the normal for me, 4.4L/100km so I don't know what's going on really.
     
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