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Leaking tons of oil

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by weenusinaprius, May 21, 2024.

  1. weenusinaprius

    weenusinaprius New Member

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    2011 Prius is losing quarts of oil a week. I'm familiar with the egu get clogged and oil being burned on the piston. I believe this is happening but wondering if this also causes a major oil leak? The passenger side engine area looks soaked, leaving tons of drips every where I park. Any advice is appreciated! I'm gonna clean out the egu, intake and throttle body this weekend.


     
  2. bisco

    bisco cookie crumbler

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    pull the aero panels off underneath the engine and inspect for puddling. anything on the ground where you park?
    you should clean the engine off and look for seepage and where it originates. how many miles on her?
     
  3. weenusinaprius

    weenusinaprius New Member

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    Oh yeah. Oil everywhere I park. 143k miles.
     
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  4. ttou68

    ttou68 Active Member

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  5. PTS

    PTS Member

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    Usually it’s a timing chain cover leak, which is on the passenger side. Many have experienced this on their factory sealed engines.

    The oil filter is also nearby as is the timing chain tensioner and the low oil pressure switch.

    However the timing chain cover just has a “form a gasket” seal and covers three separate assemblies with seams on each. If bad they leak when the engine is running.

    A clogged pcv or aftermarket catchcan installation can blow formed in place gasket seals.
     

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    #5 PTS, May 21, 2024
    Last edited: May 22, 2024
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    Some quick basic checks for a leak of that significance

    Verify oil fill cap is installed
    Verify oil filter is properly installed.
    Maybe even verify the drain plug.
    Quarts per week is a huge leak and should be quite obvious, potentially becoming a catastrophic failure while driving.
     
  7. PTS

    PTS Member

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    Some gen3 oil burners use a quart every 600 miles. Add a pumped oil leak and you go through a lot of oil.

    The solution is not a $1200 timing cover reseal. A rebuilt engine is the way to go.
     
  8. Danno5060

    Danno5060 Active Member

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    With a failed head gasket, you could also get excess pressure in the crankcase. That can cause oil leaks to appear everywhere.

    You can also get excess combustion gasses in your oil. Do you smell engine coolant when your engine runs? Does your oil look excessively black when you change it?
     
  9. Tombukt2

    Tombukt2 Senior Member

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    That kind of leak is huge I have the oil leaking during driving in a generation 2 that to get from the top dot full down to the bottom dot indicating oil is missing in a good way not is 12 or 14 days very consistent actually there are no leaks no drips nothing on the ground nothing on plastic nothing this is all getting burnt somewhere. I have a generation 3 actually two of them One has had a timing chain tensioner or oil pressure sensor or whatever over there on that side of the cover leaking for a long time but it doesn't leak anything worth discussing It's mostly vapor makes the side of the timing cover ugly but that's about it You never see it on the stick I haven't had the luxury of having the FIPG blown out of the timing cover or any of that even when I had to take my timing chain cover off and a head gasket was being attempted there were no problems with the FIPG on the timing cover The mechanic had hell getting it off The FIPG did a very good job.
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    Replacing multiple quarts, weekly, eliminates the need for oil changes.....I doubt it has time to be anything other than the new light gold color
     
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  11. MrPete

    MrPete Active Member

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    Oil on the ground like that is pretty serious leakage. Definitely find the source! I would guess it is LESS likely to be a serious engine issue, since you're not burning the oil. ;)
     
  12. wheelsup

    wheelsup Junior Member

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    Video isn't working but check the oil pressure sensor. $15 at Autozone. Mine went a few months ago, super easy to repair and it was leaking a ton of oil on passenger side of engine, on the back side.
     
  13. Tombukt2

    Tombukt2 Senior Member

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    But were you seeing that oil on the ground from that sensor leaking on the back side usually you see it's a vapor coming out of there and it just clings to the timing cover and all down the side but when you reach down at the very bottom at the edge of the oil pan engine block lower put your finger down there there's almost nothing certainly not any dripping so the look is a lot worse than what's really happening with the oil sending unit the o-ring goes bad in those are the hermetic seal that's made between the plastic and the metal and generally vapor comes out they can get worse and lead to a small drip but it's usually very very minimal and you never see it on the ground which is why no one ever does anything about it. Like when it's running out of a valve cover and running down the edge of the timing cover or what have you and it's just missing the exhaust manifold and going straight down the side of the engine hitting the plastic building up enough on the plastic to run down the plastic to actually get to the ground yeah you've got something going on.
     
  14. wheelsup

    wheelsup Junior Member

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    Honestly this is hard to read, I read the 10 words or so but without punctuation I had to stop.

    The leak was from the oil pressure sensor, it was all over the ground. A drop every couple seconds. Replacing the sensor fixed it completely.
     
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  15. Tombukt2

    Tombukt2 Senior Member

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    Exactly so we weren't leaking tons of oil like a hole in the block or a hole in an oil pan It was just a small drip from a sensor It would take quite a long time for that to show up on the stick I do imagine but maybe not if you're out driving everyday and putting some miles on the car