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Slow oil leak on Gen 2

Discussion in 'Gen 2 Prius Technical Discussion' started by Evan Armstrong, Jan 21, 2023.

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  1. Evan Armstrong

    Evan Armstrong New Member

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    I guess that's a good point, it's got 247,000. Just an old one. That said I was considering applying a bead of gasket maker on the seam on the outside just to see if it would subdue the leak, even temporarily. Would help me diagnose.
     
    #21 Evan Armstrong, Jan 25, 2023
  2. Evan Armstrong

    Evan Armstrong New Member

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    I think that you may be right about the rear main seal. If so any recommendations on oil additives to soften the gasket? Perhaps even torque specs for the bolts to see if If any are loose? At this point those are my options, other than letting it drip. I'm too inexperienced and don't have the tools to do the job properly. Not worth it for the age as well.
     
    #22 Evan Armstrong, Jan 25, 2023
  3. Tombukt2

    Tombukt2 Senior Member

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    Yes until the engine fails and needs to be lifted out of the car it's probably not worth doing That's why I was asking how long it takes and how much driving for my car to be low on oil down to the tip of the stick that's a quite a few tanks of fuel so 1,500 mi or better. So the cost of that is not really too too bad might even be more like 2000 2500. So I can't really justify pulling the engine and doing whatever which in my case I would just change the engine I have a low mileage sitting here and I just haven't felt the need to rip it out and drop the other one in other than the two quarts of oil or so that I would save every 3,000 mi or 2000 whatever it is. So it doesn't seem the work is warranted yet And if the car was sitting a lot like it technically should be now it's certainly wouldn't be worth doing I don't generally put this kind of miles on the cars anymore but the last few months I've been running a lot.
     
    #23 Tombukt2, Jan 25, 2023
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  4. pasadena_commut

    pasadena_commut Senior Member

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    Put some fluorescent dye in the oil, clean all the crud off the bottom of the motor, and run it briefly. Then inspect with a UV flashlight and the proper glasses. It is much easier to find leaks when they glow green. Even the first few drops coming out are usually visible.
     
    #24 pasadena_commut, Jan 25, 2023
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  5. mr_guy_mann

    mr_guy_mann Senior Member

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    No additives. Most are "seal swellers" that (sometimes) can soften old rubber- then it can harden more. Don't want to do that to
    o-rings and stuff in the oiling system

    I have never found external RTV application to do much of anything.

    Posted via the PriusChat mobile app.
     
    #25 mr_guy_mann, Jan 26, 2023
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  6. Evan Armstrong

    Evan Armstrong New Member

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    Thank you kindly for that information. The next step is UV dye since the leak is so slow, I am unable to tell where it's coming from. Will post pictures when it is done. Regardless I do believe it is either the previously mentioned seam or the rear main seal. Repairing just sounds like a pain. Thank you all for the fantastic information, It is much appreciated.
     
    #26 Evan Armstrong, Jan 27, 2023
  7. Evan Armstrong

    Evan Armstrong New Member

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    Update:
    So I replaced the PCV valve just for the heck of it, and not the leak which was actively dripping is now barely forming a drop! While it does drip anymore, there is still an extremely slow leak. With the knowledge that you all have do you have any other suggestions about parts I can clean or replace to improve this situation? Maybe oil sensors or even solenoids? I am not too savvy when it comes to those parts interacting with oil pressure and causing a leak. Just know that the PCV valve replacement made a very significant impact on the leak.

    On a side note I was not able to find any torque specs for the PCV valve and essentially just tightened it similarly to the original, leaving some threads exposed. This feels wrong to me, any suggestions?

    I will still follow up with UV dye but I have a feeling that this may be a pressure issue causing seals to fail.
     
    #27 Evan Armstrong, Feb 10, 2023
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    I’m thinking ~20 ft/lb but I can check tomorrow morning.
     
    #28 Mendel Leisk, Feb 10, 2023
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah it's 20 ft/lb, see attached.
     

    Attached Files:

    #29 Mendel Leisk, Feb 11, 2023
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  10. Evan Armstrong

    Evan Armstrong New Member

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    UPDATE:

    Used UV dye, unfortunately, it appears that the leak is coming from the exact spot it is building up at. I found no other indications of it leaking from any other seams. Please see the photos that are attached. I do see a small 'hole' along the seam that is shown in the pictures, have no clue if this adds to the issue or not.

    My proposed solution is to leave it. It is so so so slow now upon replacing the PCV valve oddly enough. Unless there are any further suggestions to replace similar parts as the PCV valve or perhaps even clean the tube it connects to, then I will leave this issue to rest. I am going to tighten down the PCV valve a bit more in the future and keep an eye on the oil level. Unless this sub has any way forward I am afraid I just have a leaky Prius.
     

    Attached Files:

    #30 Evan Armstrong, Feb 12, 2023
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