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Good morning all,
Element concentration trends from several oil analyses supposedly offer some indication of what is happening inside the engine. I have a 2010 (new) 912 ULS with about 265 hours on it. I change oil(Aeroshell Sport plus), filter and do an oil analysis every 30-40 hour. After about 130 hours the iron concentration started trending up. The magnetic probe and filter are free of metal. Friends tell me it just the gears settling in. Does anybody recognize this iron concentration signature and know what it means? See graph attached.
Tony
Garrettoilanalysisplot.pdf (You do not have access to download this file.)
  • Re: 912 ULS oil analysis

    by » 12 years ago


    Wearcheck is recommended as they have an extensive Rotax database so they can identify our unique characteristics (geared engine with dog hub/dog gear torsional dampener, nicasil cylinders). They also have offices worldwide.
    Some aviation oil analysis companies with Lyc/conti experience, but no Rotax experience, will be alarmed at the iron content in the average sample but it is normal as we have gears and a metal-to-metal torsional dampener (don’t worry; the dogs are built to last despite the amount of wear induced on them)
    Typical wear element of iron includes: gearset and dogs, cams/tappets, shaft journals, and piston rings.
    Average 100hr TTSN sample: Iron - 20 mg/kg

  • Re: 912 ULS oil analysis

    by » 12 years ago


    Roger Lee, Would you mind giving your opinion on the increasing iron concentration?

    Thanks, Tony
    Garrettoilanalysisplot.pdf (You do not have access to download this file.)

  • Re: 912 ULS oil analysis

    by » 12 years ago


    Hi Tony,

    It is something that should be watched. You can have spikes on certain things at different times and things that can influence the readings is if you caught your sample at the beginning of the flow, the middle or the end of the drain and especially how long you leave an oil in service. I tend to change mine every 50 hrs and I use 91 Oct. Even sampling cold verses right after a run with a hot engine can influence the readings. Try to have a warm engine and catch the sample middle drain and do it the same every time. The switching of the fuel may have had an influence too, but don't stop using the 91 oct. Have you changed brand of oil? Take the next sample or two and watch the readings. Like I said you can have a spike and readings should be looked at as trends. If it continues to stay high or continue to climb then further investigation is certainly warranted. You should also be keeping a watch on your oil magnetic plug. Another thing that can be done (like doctors) is seek a second opinion and in your case try another lab to confirm.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell


    Thank you said by: YEN NIEN YU

  • Re: 912 ULS oil analysis

    by » 12 years ago


    Thanks Roger
    Tony

  • Re: 912 ULS oil analysis

    by » 3 years ago


    Is there any service instruction or bulletin issued by Rotax about this oil analysis test?

    Faisal

    Regards 


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