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Car burning oil, weird smell

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Starcheckered, Dec 6, 2014.

  1. Starcheckered

    Starcheckered Junior Member

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    I took my car in on Wedneday and found out that it's been burning oil. It's a 2008 with 155,000 miles. The mechanics told me that if I use a heavier oil that the oil won't burn up as fast, so they did an oil change and put 10W40 in my car (in the manual it says 5W30.)

    Ever since the oil change (it's Saturday, and it was on Wednesday), my car has been emitting a burning smell. When the heat is on and the vents are selected to circulate from outside, I can smell it. When the vents are turned on to circulate air that's already in the car, you can't smell it (so you can't just smell it with the windows rolled down either, or standing outside the car, only inside the car when the heat/AC vents are on). You can't smell it when the vents are turned off. Any ideas what this smell is? Should I take it back in/should I call? I only haven't because I assumed it was probably related to putting the different oil in my car.

    I've driven about 100 miles since the change and my car isn't acting strange or different. The smell is it. It was really, really strong on Wednesday (enough that my kids even complained and asked to roll down the windows) and now is not very noticeable, but I can still tell it's there (esp. since I'm looking for it.)
     
  2. valde3

    valde3 Senior Member

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    How much oil does your car use? It might not be good idea to use thicker oil. Does it only burn oil so no leaks? Maybe its oil spill when filling it with oil?
     
  3. frodoz737

    frodoz737 Top Wrench

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    Going to a heavier oil is still good SOP on worn out motors, but "should not" cause the smell if it did not already exist. Check for obvious leaks or spillage and if nothing is found return to your mechanic to have it checked out.
     
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  4. The Electric Me

    The Electric Me Go Speed Go!

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    I guess my question is, HOW MUCH oil is it burning?

    Toyota recommends the lighter, synthetic oil. If you're burning oil at a rate that is slow enough, where just keeping an eye on the level and adding oil as needed works? That might be the route I would go with.

    If your burning oil at a much higher rate? You're probably closer to much more expensive corrective alternatives. Think engine rebuild or replacement.

    I've owned older vehicles that burned oil, BUT not older hybrids. With the stop and go nature of HSD? I think I'd want the lighter oil as long as is possible. It's true heavier oils can reduce oil burning and consumption, but if it's going against the recommendation of the manufacturer it is at best simply a stop gap solution masking the real problem.

    I'd also check to make sure you don't have a leak or otherwise. The smell of oil in any case shouldn't be too strong.

    I've actually driven vehicles for years and years that "burnt" some oil. An attentive top off once a month or so, was OK with me, and the vehicle remained viable. I've also had relatives where the problem simply got worse and worse, until they had billowing smoke and it was time for a new car.
     
  5. bisco

    bisco cookie crumbler

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    toyota doesn't recommend synthetic in the gen II. maybe they spilled some oil and it pooled, so is burning off?
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe pop the hood and check if they put the oil fill cap back on properly.
     
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  7. Former Member 68813

    Former Member 68813 Senior Member

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    time to top off oil more often.

     
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  8. cmoore50

    cmoore50 Junior Member

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    I don't want to be rude, but where are you getting that information? Do you have any sources?
     
  9. uart

    uart Senior Member

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    Most likely they just spilt some oil during the change and some is burning off on the exhaust. But do check that the oil cap has been placed back on tight. Also check that they got the oil level right while you're at it.

    The change to 10W40 oil has nothing to do with the smell.
     
  10. Britprius

    Britprius Senior Member

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    In the UK Toyota specifically state synthetic should be used, but I agree an oil spill when the car was being refilled with oil is likely to be the problem.

    John (Britprius)
     
  11. css28

    css28 Senior Member

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    If it were me I'd have kept the 5W30 and added a quart when needed.
    If it gives you an extra 2 or 3 mpg it's probably cheaper and better for the engine.
     
  12. Britprius

    Britprius Senior Member

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    Another thing to consider when going to a "thicker" oil is outside temperature. Low temperatures with a thicker oil can cause a trouble code fore engine failed to start due to a lower turn over speed.

    John (Britptius)
     
  13. bisco

    bisco cookie crumbler

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    not rude at all. it's in the manual. when i say 'doesn't recommend', i mean it's not the gen II spec., where it is in the gen III manual. gen II comes from the factory with dino oil, am i mistaken? i always used dino in my '04 and '08. not to say that synthetic can't be used, of course it can.
     
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  14. Easy Rider 2

    Easy Rider 2 Senior Member

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    First, this sounds like you have an actual oil LEAK and not increased usage due to engine wear (maybe a bit of both).

    Oil dripping on a hot manifold, for instance, would have a very distinctive smell; so would a coolant leak but dramatically different.

    I suggest that you check the oil and coolant levels and then take it BACK to the shop again.
    [edit] And since it showed up when it did, I'm firmly in the camp with those who say that a little oil might just have been spilled during the change. But please DO check the level immediately.

    Probably not anything serious but it could be. A large amount of oil getting into the CAT converter can cause it to overheat, smell bad AND possibly cause a fire.

    Second, I would not bother putting in heavier oil unless it is "high mileage" type because some of the loss might be from worn seals that can be helped by the extra additives.
     
    #14 Easy Rider 2, Dec 7, 2014
    Last edited: Dec 7, 2014
  15. uart

    uart Senior Member

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    I have to agree, especially coming into winter. To be honest I think that Starcheckered would get greater benefit from checking the oil level more regularly than any changes of grade.

    Having to wait for a visit to the mechanic before finding that you have an oil consumption issue is rather like not finding out that your trousers have a huge rip and your arse is hanging out until after a trip to the taylor.
     
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  16. dorunron

    dorunron Senior Member

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    Agreed, if the op would simply check his/her oil when purchasing fuel or at least once a month, then they would know when the car started using oil. A ICE simply does not start using oil overnight UNLESS it is abused (overheated, oil ran dry, etc.) It usually happens gradually and over time.

    By checking the fluid levels regularly, no motor vehicle operator should ever find themselves saying "my car is using oil". "Never did this before". "Just found out when they changed the oil"...

    Ron (dorunron)
     
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  17. valde3

    valde3 Senior Member

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    I agree to this. Especially I’m amazed that people can write long stories to internet (takes time) but not check there oil (is a lot faster).

    But sometimes engine can suddenly start using oil without being abused. With some older Toyota engines you can almost diagnose the problem of gummed up oil return holes and/or piston rings if problem starts suddenly. And some have reported that they had this problem in Prius or that the quick fix for this (diesel/solvent into cylinders) did fix there oil consume problem.
     
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  18. bisco

    bisco cookie crumbler

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    i wonder what the mechanic found, that led him to tell the o/p he was burning oil?
     
  19. uart

    uart Senior Member

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    Most likely he just found a low oil level.
     
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  20. Easy Rider 2

    Easy Rider 2 Senior Member

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    Or he "found" the mileage on the ODO.