Oil consumption at 136k miles - too high

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Daddy Dave, Sep 18, 2015.

  1. Daddy Dave

    Daddy Dave Member

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    The oil consumption started around 90-100k miles. My wife mostly drives the car so I just check it and fill it without keeping track of mileage. Last week I had a lot of driving to do so I topped off the oil before starting my trip and put a 5 qt 5-20w bottle in the back. I've been through two liters in 2100 miles! Sheesh - I'm ticked off. I do my own oil changes at least every 10k miles, always use 0-20w or 5-20w full synthetic oil (usually Mobil 1). I replaced the spark plugs at 119k miles per maintenance schedule.

    Besides the oil consumption, since 115k miles the engine can get into a mode where it misses a little bit at low power once it is completely warmed up. I have a good code reader and nothing ever shows up. I expected the new spark plugs would fix it, but they didn't change anything about how it runs. It is slowly getting worse. I'm going to wait until a code in the ECU is set before fixing it. It could be an ignition coil. I suspect it is an O2 sensor which causes the AFR to be too lean which makes the mix hard to ignite. Time will tell. It runs fine when cruising at highway speeds.

    We bought this 2010 Prius III, not 3, new in October 2010. The only out-of-the-ordinary thing we do is live in northern Wyoming where it can be very cold for a long time. We drive 85 mph for long distances to go shopping and visit friends. The gas mileage is the same as it has always been. It varies between 42 and 50 mpg in the summer and 35 and 45 in the winter.
     
  2. PlumbersCrack

    PlumbersCrack Junior Member

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    Welcome to the club. I'm in a bit higher mileage then you are but this car has seen the dealership for every single maintenance that was required. My gas mileage of summer, down into the mid thirties, and it drinks oil. I have a similar thread that I started a few weeks ago but have recently found that all my spark plugs had oil on the threads. I have not been able to check compression due to the size of most adapters not fitting but I know the results will not be friendly. I will follow this thread and hopefully you come to a better computer that I have. Good luck.
     
  3. Beachbummm

    Beachbummm Senior Member

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    change you PVC valve and hope for the best..theres videos on you tube that will show you where it is and how to get to it..
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    The miss might be Exhaust Gas Recirculation system related. The most accessible portion is this pipe, connecting the PCV to intake manifold. It has a flange at both ends. The EGR end is easily accessible. The intake manifold end is quite difficult to get at, obscured by piggybacking connections. But it can be done, just a pain.

    Get that off and see how clogged it's getting, it'll be symptomatic of the the rest of the circuit is like. I think you can just see the pipe here, peeking through between inverter and air filter housing. The latter needs to come off for access.

    Capture.JPG

    Better pic, EGR end of pipe at centre:

    image.jpg
     
    #4 Mendel Leisk, Sep 18, 2015
    Last edited: Sep 18, 2015
  5. Daddy Dave

    Daddy Dave Member

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    I'll give that a try as soon as possible. We used to hope for 400k miles out of this car since our two of our last three Toyota's we sold when they reached 300k and were still running strong.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, 3rd gen is the first to implement EGR, and a lot of owners are seeing clogging. Pretty much everyone who looks I guess, lol. To clean the whole thing is an involved chore, the cure might be worse than the disease. At least pulling off this pipe you can get an idea.
     
    #6 Mendel Leisk, Sep 18, 2015
    Last edited: Sep 18, 2015
  7. PlumbersCrack

    PlumbersCrack Junior Member

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    Hopefully changing the PCV valve works for you because it did not work for me. It's only about a $13 part of so and takes about 30 minutes worth of time.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Oh, egg-on-face: I meant to say Exhaust Gas Recirculation, EGR, not PCV, in my previous posts. Will fix.
     
  9. Daddy Dave

    Daddy Dave Member

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    Your engine compartment sure is clean! Mine is full of dust and leaves.
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    That first picture is just off the net, but yeah ours is very clean. One thing that might help: I pushed these foam tubing pipe insulation pieces onto the seams along the junction of engine bay and fender. When you drop the hood this seals pretty much all the edges, whereas stock you've only got gaskets at the front and back. Also, I go over it with an old paint brush, a boa duster, then hit it with a leaf blower every so often. I'm a little nuts about it, lol. Plus, we're only around 56000 kms, garage parked.
     
  11. jadziasman

    jadziasman Prius owner emeritus

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    A liter every 1000 miles is excessive. Do you know what the engine rpm is when you're driving at 85 mph? The 1.8L engine in the Gen 3 must be spinning slower than the 1.5L Gen 2. Nevertheless, it's a well known fact that OC increases as engine rpm increases. You should see a decrease in OC if you drove at 75 mph instead of 85 mph.

    It's unfortunate that you have this problem with such low miles (for a Toyota). I hope you find a fix for it.
     
  12. CR94

    CR94 Senior Member

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    Toyota claimed 2200 RPM for the 1.8L at 120 km/hr, compared to 2500 for the 1.5.

    I hope someone soon determines what the oil-guzzling 1.8s have in common in their history, so I can avoid it---if it's avoidable!
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Isn't it obvious: dust and leaves in the engine bay. :ROFLMAO:
     
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  14. Daddy Dave

    Daddy Dave Member

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    OK - I've read up on the EGR valve and watched a YouTube video about how to get to it. I'm convinced that is what is going on. PlumbersCrack - the EGR valve is large and has a motor on it and is $80 on Ebay. It is located under the air cleaner box. It doesn't look like a $13 part that would take 30 minutes to replace. It may be an artifact of running in cold weather all the time. I can imagine how oil could condense inside it and collect on the walls when cold. If I open it up and find that it looks like the pictures on YouTube and is filled with gunk, I may attempt wrapping it with some exhaust insulation. Maybe...

    Unless someone here suggests otherwise, I'm going to just take it off and clean it instead of replacing it. I wouldn't be surprised if that is what is also causing the misfiring at low power.

    My car is just shy of 5 years old and 150k miles. I have a personal vendetta against the local dealer due to an oil change fiasco and lack of apology on another vehicle. If someone here thinks it could be covered by the emissions warranty, I'll swallow my pride and take it in. I'm positive that in the end I'll figure it would have taken less time and expense to just do it myself.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    One thing, and this continues to nag me: the pipe between EGR and intake manifold seems like the canary in the coal mine. The EGR valve proper is back a ways, and has coolant hoses connected. At the back end it connects to the exhaust manifold. That connection is (maybe) best accessed from the underside. At the other end, I suspect the intake manifold is prone to gunk build up too. This is the first Prius generation to have EGR I hear, and cleaning it seems a can of worms.

    But yeah, check the pipe first, and at least you then have an idea of how bad it is.

    There's some pictures and thoughts in this thread:

    Prius III engine knocking at high torque low RPM (solved) | PriusChat

    A wack of pics on the last page too.

    There's another thread, but I'm having trouble finding it. By member Christian Cool, or something similar to that?
     
    #15 Mendel Leisk, Sep 19, 2015
    Last edited: Sep 19, 2015
  16. kenichols29

    kenichols29 Active Member

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    If you have oil on your spark plug threads it sounds like the spark plug tube seals are leaking. A new, valve cover gasket set will have the tubes seals included.
     
  17. CR94

    CR94 Senior Member

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    Because the EGR is cooled (thanks to the coolant hoses Mendel mentions in post #15) I'd doubt wrapping it would have much effect on condensing gunk.

    Good luck, and let us know how it goes.
     
  18. Daddy Dave

    Daddy Dave Member

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    Good point about the cooling of the EGR. Now that I've chased through a couple of threads, I'm convinced this is going to be a constant problem. It gets blocked such that most of the exhaust is dumped into the first cylinder or two and never reaches the last. This would explain why the engine miss feels like it is on one or two cylinders and not randomly across all cylinders. It is a design flaw. A layman's guess is the oil vapor condenses on the walls of the EGR tubes and intake manifold and eventually plugs up the passages. That doesn't explain why it causes oil usage to increase. Any thoughts?

    The other thought is though I've never used dinosaur oil, I don't always spend $38 for 5 quarts of Mobil 1 0-20w and I've never been to the dealer to buy genuine Toyota 0-20w. Is this a case for always using the right oil? I don't think I've ever put 10-30w in it. I've often used 5-20w. Always full synthetic oil.

    I'd be OK with having to perform 30 minutes of passage clearing every six months. Maybe that's what it will turn into as preventative maintenance.
     
  19. Daddy Dave

    Daddy Dave Member

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    This is a dangerous question and I deny ever having asked it. I must have read it somewhere or picked it up from a Dodge website. What are the negative points associated with blocking off the EGR pipe completely? It is easy enough to manufacture a stainless steel plate.
     
  20. PlumbersCrack

    PlumbersCrack Junior Member

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    I've completely removed the EGR system and cleaned that including the EGR cooler in the past with no help with my oil burn problem. The PCV Valve is what is a 13 dollar part and took me about 30 minutes to replace. Neither changes fixed my oil burn issue.
     
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