Slow oil leak on Gen 2

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

  1. Evan Armstrong

    Evan Armstrong New Member

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    Just bought 05 Prius with 247K miles. Just did an oil change and transmission fluid change.

    Car has a slow but present oil leak that stays down low. Attached are pictures. My thoughts are to tighten bolts in the picture to torque spec and see what happens. Already checked oil plug, and transmission plugs. It is engine oil anyways.

    Originally I ruled out the filter, but looking through the pictures now I am suspicious. Could the leak be coming from the front of the engine and running down? Again, oil stays low on the engine. Vehcile did have the same leak prior to the oil change so to me it isn't likley the filter. Any help is much appreciated. Thank you.
     

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  2. PriusCamper

    PriusCamper Senior Member

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    There's lots of places oil could be leaking from... You got lots of great photos of everything too. That will be helpful in future stages of the diagnosis. Next step is to clean and inspect every nook and cranny for signs of trouble, as well as your mention of tightening bolts to ensure nothing is loose. Probably no need to check torque, just make sure they're all same tightness by tightening them a very small amount. Once the engine is clean and you put some miles on it, the location/significance of the leak will likely be more apparent. Too much of a mess to say for certain right now.
     
    #2 PriusCamper, Jan 22, 2023
    Last edited: Jan 22, 2023
  3. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Best move is to clean it, give it an opportunity to leak fresh and then take another look. No need to pick up any wrenches yet.

    You can get underhood degreaser sprays to help. Low pressure water to rinse. Think about where the runoff goes.
     
  4. Tombukt2

    Tombukt2 Senior Member

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    My engines just like that when I got the car as soon as I cleaned it with super clean two or three times and got it whistle clean I had no leaks so apparently somebody was spilling when they were filling whatever those oil filters the 4600 or 4960 or whatever it is they almost never leak and they're upside down and all that great setup one NZ is great stuff I love it generally if you clean it off you'll find most people are just spilling oil because in the latter stages of their life every 2 weeks if the car is driven a good bit you'll be down on the tip of the oil stick or close and you add about 1.7 quarts or whatever and it brings it back up to full and you're good for another two or three weeks It just works out that way and it'll last that way with cheap oil until 500,000 mi so this kind of no point in fixing it the little bit of oil you'll use to get to that mileage will be what I don't know three $400 worth of something maybe out of that whole time if that because once they get up to a few owners and 250 plus thousand miles you are using a little oil oh well Don't make it too costly It doesn't need it that point to be full synthetic and meet every criteria of the space shuttle and all that kind of nonsense It can be just cheap Walmart oil dino oil whatever It won't matter at this stage of the game.
     
  5. Evan Armstrong

    Evan Armstrong New Member

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    Thank you for the replies! I will clean it up with some engine degreaser today. I've done it in the past but Everytime I take a look it always looks the same! Will post some more pictures if anything changes. I have a hunch to think maybe just a very slow gasket leak due to age. If there are any specific spots to check I'd be happy to do so. Thank you again
     
  6. Evan Armstrong

    Evan Armstrong New Member

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    Update: took it for a 25 mile drive. Leak is still slow, stopped and degreased underside as best as I could. I am more confident now that it is this main engine gasket leaking as shown in the picture (pointing with ratchet). You can see the nodule sticking out where the gasket is. It makes sense since the bolt directly beneath it is covered in oil. Also the bolts I saw were indeed tight.

    Let me know what you guys think, any fixes for this besides the obvious and far too expensive one? What's a long term solution, I hate having it leak, despite how slow it is.
     

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  7. Tombukt2

    Tombukt2 Senior Member

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    Well if there's a gasket surface which there will be where the two pieces of aluminum meat together there may be no gasket it may be FIPG Toyota uses this a lot it's gray material It makes the gasket You squirt it on the part that you have off after cleaning you allow it to skin 15 minutes or so then you offer the part up and you bolted up properly and then torque it and then a little bit of that FIPG may squeeze out If you're really good at setting it on the gasket flange with the proper bead you may not see it squeeze out it'll come right to the edge and stop If you look at how it's done on the parts that it's done to you see very little squeeze out when the parts are mated this is how it should be It is also important that you allow the FIPG to skin that means it's dryer than when you applied it to the flange It turns almost to like a rubbery substance you can touch it with your finger lightly and it won't be on your finger when you lift it the product has skinned is the term now it's ready for assembly most people can't wait for the skinning to take place they're in a big hurry they think they're just supposed to squash it together and watch it all squeeze out and they're done and then they may have leaks
     
  8. Evan Armstrong

    Evan Armstrong New Member

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    Ah I see. Thank you Tom for the detailed response.

    I am very apprehensive to look into separating these pieces however, while I am somewhat mechanically inclined I do not believe I have the tools or knowhow to properly do that job. I've used gasket maker before, but in this case I feel like the most I could do is put some along the seam on the outside.... Not ideal I know, but it seems like me only option.

    Is that even worth doing? Am I overestimating this job?
     
  9. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

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    That time varies. With the timing chain cover for example: IIRC after application of the Toyota spec FIPG you’re expected to have the cover installed and all its bolts torqued very quickly, in less than 15 minutes total. I’ll dig it up later.
     
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  10. ColoradoBoo

    ColoradoBoo Active Member

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    It can be hard to find where it's coming from...might even be a couple of bad gaskets which aren't hard to have replaced.

    In the meantime, check oil levels often and top off if running low...you don't want to overheat that little engine. You don't have a good local mechanic who can check it over for you?
     
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  11. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

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    Here for example is the second gen oil pan install instruction; saying after application of the spec'd Toyota FIPG install the pan within 3 minutes.

    FWIW in their videos Gasket Masters use a non-Toyota FIPG, with a much longer set-up time.
     

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  12. Tombukt2

    Tombukt2 Senior Member

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    I guess that's some kind of instructions for the two z engine only standard FIPG practice well would be about right within 15 minutes that gives the stuff time to skin so it doesn't just squeeze together and squirt out of course using too much yields the squirting out problem too so 15 minutes sounds about right I don't think Toyota would tell you to squirt Toyota gray FIPG on the part and then be immediately mating it up but it's possible I haven't read the instructions for the two z engine but I've been using FIPG since it started being widely used in this country it's even right on the package of the FIPG it tells you to allow it to skin.
     
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  13. Evan Armstrong

    Evan Armstrong New Member

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    Yes, it is difficult to pinpoint. All I can tell you for certain is that the leak is coming from down low, just below the seam I point out in the picture on the engine. Everything above it is bone dry ruling out the valve cover gasket. I think that is a good suggestion, take it to a local mechanic. I prefer to find it out myself if possible, just have had bad experiences being up-charged from the last mechanic I went to. May just have to bring it in for a proper diagnosis. Also, I have been checking the engine oil regularly and I have yet to notice it run low. While oil is present on the pavement it is a slow leak for sure.
     
    #13 Evan Armstrong, Jan 24, 2023
    Last edited: Jan 24, 2023
  14. Evan Armstrong

    Evan Armstrong New Member

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    Thank you Mendel, for that information, unfortunately, I am unable to open that document, perhaps an error on my end? Also, I am not so confident it is the oil pan that is leaking, as there is oil present up higher at that seam I showed in the picture. I really am not sure what those mating surfaces I am looking at even are in the photo. It is closest to the drain bolt for the coolant is all I can make out, and above the oil pan mating surface.
     
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  15. Tombukt2

    Tombukt2 Senior Member

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    I can't tell where you are in the car need a picture from further back but regardless it should be pretty easy to tell and you're saying down low not the valve cover gasket and there's not a whole lot up there how long does it take to show up on the stick That's the big question?
     
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  16. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

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    Try again, plus a few more that might be relevant. If you see anything else just let me know in this thread.
     

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    #16 Mendel Leisk, Jan 24, 2023
    Last edited: Jan 24, 2023
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  17. Evan Armstrong

    Evan Armstrong New Member

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    Sorry about the pictures, I will try to get a better one this week for a better view. In the meantime, I snagged this one offline highlighting the suspected area of the leak.
     

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  18. Evan Armstrong

    Evan Armstrong New Member

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    Takes a long time. Did about a 40 min 25 mile drive the other day and couldn't even tell a difference.
     
  19. Tombukt2

    Tombukt2 Senior Member

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    Yes generally I'm looking for a time frame like a couple of weeks or something like that so I would let it do its thing for a week check the oil no movement another week check the oil eventually at some period you'll see a noted drop on the stick. And then that gives you a baseline of time and not that time baseline is fairly long like a few weeks it's probably not really worth fixing The gasket that you're showing is the center section of your engine if I'm not mistaken it would be quite a big to do to take that apart to fix a small drip that takes a few weeks to show up on your stick at seriously over 150,000 mi or better but I don't know what your real mileage is it's just a guess. I don't have any leaks that I can tell I'm using some oil it takes about 4 to 5 weeks for me to get from the full mark on the stick perfectly full not over or under and then to get down to the tip of the stick is the time stated above that kind of oil usage is going to be relatively expensive to fix so I just run cheap oil and let it rip I'm like right at 400k heading to 600 the little bit of oil that I use the cheap stuff is not going to make or break anything at this point other than the pollution but still on the sniffer it's quite clean
     
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  20. mr_guy_mann

    mr_guy_mann Senior Member

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    IF your leak (seep) is the upper oil pan, then yes- it's a moderately big job. Gotta clean all the old RTV off. The annoying part is trying to keep the sealing surface dry as you apply sealant to the pan and get it in position. Oil will constantly ooze and drip from inside the block. Having oil on/in a RTV seal will guarantee a leak. Tough job for someone inexperienced in doing it.

    That said, your leak could be something like the rear main crankshaft seal. Possibly even a valve cover leak higher up (but less likely, as the back of the block looked ok). All I can tell from your pics is the bottom of the bell housing area is wet.



    Posted via the PriusChat mobile app.
     
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