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Burning oil at same rate regardless of oil thickness --- What does it tell us?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by AllenZ, Dec 13, 2013.

  1. pmike

    pmike Member

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    At your usage rate you might not have any need to change your oil just keep topping off. I wonder if the oil filter can be removed without drain all the oil. Could just change it every 5-10k and just keep topping off.
     
  2. AllenZ

    AllenZ Active Member

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    Yes you can change filter with a couple of dripping of oil only, without replacing oil. But since you already lifted car, and oil is really cheap, why not drain and fill new ones?

    I think it is a good idea in general to put in 20% of MMO to clean the carbon, from time to time, if your mileage is higher than 100K. It does not clean everything, but for me, the oil cap is cleaner for sure after using it.
     
  3. JC91006

    JC91006 Senior Member

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    I just completed a test of 20% MMO for 10,000 miles (did it twice), didn't notice it did anything for my 2006 with 128k. Still burning the 1qt every 1500 miles.
     
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  4. CBarr31

    CBarr31 Active Member

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    AllenZ,

    Sorry to hear your experimentation with controlling "The Burn" are not progressing as well as mine. Ema's oil burning has stabilized around 1 quart every 3,000 miles as long as I run pure E0 gas in her. I could do 3,000 mile OCI's but I top off at 3,000 then do a oil and filter change at 5,000. I think I am going to make the switch to 10W40 exclusively at my next oil change and just run that. I have ran it as a "test" some changes and it might help the oil burning slightly and it has virtually no affect on MPG so why not run the thicker oil is my thought. Since Ema has over 385,000 now it isn't like it is going to hurt her, LOL.

    I imagine you are getting close to swapping out your engine if you haven't already? Be sure to post back how that goes and how it has helped with your oil burning. Running E0 I think I will be able to feed Ema oil until the Gen 4 comes out in 2016 although I am going to have to put a cat in her to pass emissions next year. Check engine is pretty much continuous now.

    Happy Driving,
    Chris
     
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  5. AllenZ

    AllenZ Active Member

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    I am going to swap engine but not in hurry. As to the thicker oil, I used 20W50 at one time, consumption is similar to 10W30. The only other cost associated with burning oil is spark plug needs to change more, plus oil of cause.
     
  6. kredfish00

    kredfish00 Junior Member

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    @AllenZ and Chris

    I am very interested in this thread as my 2010 started burning oil at about 120K. I am now at 132K and it seems to be burning 1qt/1500-2000 miles. I commute 160 miles per day so it's hwy mileage running at about 78 mph. I definitely see more oil burn when I am commuting rather than when I am driving locally in city. I am contemplating switching to 5W-30 Mobile 1 as I have been religiously using 0W-20 since I bought the car new! I changed the PCV valve and the spark plugs recently and have seen no signs of change. The old plugs looked very clean with very little in the way of carbon build up. It was recommended that I swap a qt of oil next oil change with Lucas Full Synthetic oil stabilizer which I will try. Am curious to follow-up with more info as time moves on. Warding off an engine replacement for as long as I can but am not opposed to it if it means driving the car another 150K miles! There are NO sounds coming from the engine and everything else is operating flawlessly! MPG have gone from 44-45 down to 42-43 but his could be attributed to numerous other reasons.....

    Am curious to hear your recommendations! Thanks!
     
  7. Feri

    Feri Active Member

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    The oil stabilizer is a waste of money. The oil you are using is already fully synthetic. Toyota engines will typically run for 100s of thousands of miles while using a small amount of oil. My daughter's '85 Camry has 400,000 Kms (250,000 miles approx) and uses about 2 litres (2 US quarts approx) of oil between 10, 000 km changes. She uses 10W- 50 fully synthetic.

    I have similar distance to yours on my 2010 and seemed to lose a little oil before the last oil change. I used about 1/2 litre in 10,000 KMs (6000 miles). I suspect an intermittent leak as I have now traveled 4000 km since that change and no change on the dipstick. I guess I'm saying, while not ruling out oil consumption, make sure you have no leaks before assuming the engine is burning oil. You might not see any on the pavement or under the body as the under shroud can catch a lot of it.

    Here in Aus, Toyota mandates 10W-30 as the recommended oil. Not sure why but they probably have good reasons.
     
  8. exstudent

    exstudent Senior Member

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    Got me curious. From a few searches, it essentially comes down to ambient temperature.
    5W-30 (-30C to 30C) vs 10W-30 (-18C to 40C).
    Both are multigrade/multiweight oils.
    COLD viscosity number (5W or 10W; W stands for Winter by the way) - How easily the oil flows when its cold. You want oil to flow quickly to get to all the moving parts. The lower the number, the colder the temperature can be, and the oil will still flow well.
    HOT viscosity number (last set of numbers, both are 30 in this case) - What is the viscosity at 100 degree Celcius.
    Viscosity is thickness; easier to understand as flow. Thick viscosity (high number), will not flow as fast as a thin viscosity (low number).

    Toyota apparently has determined that Australia is warmer than the US, as evidence by the recommendation of 10W-30 (Aus) vs 5W-30 (US).

    Oil has a shelf life (3-5 years depending on storage condition). Don't go nuts and stock-up an insane amount.

    I found these three sites were informative:
    Car Bibles : The Engine Oil Bible
    Motor Oil Myths and Facts versus 10W30
    Oil Specifications Explained - What does 10w40 mean?
     
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  9. jadziasman

    jadziasman Prius owner emeritus

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    Unopened containers of Mobil 1 have a "recommended" shelf life of five years which means my stockpile of full synthetic
    is good until early 2019. No worries, mate.
     
  10. Feri

    Feri Active Member

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    Thanks for those links! We also change oil more often than you. I think 10,000 sounds good to Toyota. It only harms my wallet.:)
     
  11. uart

    uart Senior Member

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    No it's the other way around Feri. The official service interval for the Gen2 Prius is 5k miles (about 8000 km) in the US, vs the 10000 km interval here in Australia.
     
  12. Britprius

    Britprius Senior Member

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    Versus the 10,000 miles in the UK/Europe.

    John (Britprius)
     
  13. AllenZ

    AllenZ Active Member

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    I believe you are at the critical point of engine life. You need to change oil more often immediately, and before you change oil, use something like Motor Flush from Gunk (pour in, idle engine for 5 min then change oil). You can add some MMO or other carbon removal additive into the new oil to at least slow the carbon deposition process, hopefully clean some existing carbon. I see carbon deposit on oil cap is reduced after using it.

    If you don't do that, more carbon deposition will lock the piston ring and damage it, causing permanent ring damage. That's where I am at now: 700 mile/qt consumption.
    And I can see that my oil is darkened much more faster now, even with fresh oil added. I think some carbon from combustion chamber leak into the oil. I drive 90 miles/day, regular oil should last 6000 miles no problem. But at 4000 miles (5 qt new oil added), oil is dirty and has to be changed.
     
  14. kredfish00

    kredfish00 Junior Member

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    I hear you AllenZ.......I intend to shorten the OCI to maybe 8,000 miles and use a flush before a change. What is the product Auto-RX that I hear some people talk about? I do like Chris' post (about Ema) that talks about using non-ethanol gasoline. I may try a few tanks of that. Could the varnish and deposits on the cylinders be caused by Ethanol? Am planning to try to keep mine going for as long as I can! Thanks for your input and keep me posted on your progress....
     
  15. AllenZ

    AllenZ Active Member

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    I added Auto-RX to oil too, nothing happened in my case, same as MMO (added about 5 qt during past 14K miles).
    From what I read, piston ring soak is effective in some cases. However, Auto-RX is very expensive ($50 for 24 oz). I would try MMO first ($5 for a qt). I guess they are similar.
     
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