Oil Analysis

[JoeRuscito]

First I’ll admit I’m quite the novice when it comes to airplane maintenance but I’m learning as much as I can.

As I was thinking through my latest oil change and doing some reading about sending out oil samples I’m wondering how often i should be sending out my oil samples. What interval is common? Every oil change?

I’m currently running 100ll so oil changes every 25 hrs. Thinking about switching to swift and having it delivered to increase the oil change interval.


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[jiott]

Everyone has their own opinion on this, but here's mine: When the engine was new and still breaking in and the whole system was cleaning itself out, I sent in oil samples every 100 hours (the first one at 50 hours). Then as things stabilized and all results were consistently good, I stretched it out to 200 hours, which is where I intend to keep it from here on out, unless a sample comes back showing a definite change and a need for shorter intervals. Basically you establish a consistent baseline, and then just keep track of changes in the trend. FWIW

[109JB]

While right now I run a 2-stroke in my Kitfox and oil analysis isn't applicable, I have owned several 4-stroke powered airplanes and I did oil analysis EVERY oil change. Oil analysis costs about $30 and is extremely cheap compared to everything else in aviation. When something starts making metal it can go very quickly and IMO 200 hours is way too long. Also, I changed oil every 25 hours because again, oil is cheap compared to engine overhauls.

[jiott]

I also cut the filter open and examine every oil/filter change, as well as examine the magnetic plug every 100 hours.

[JoeRuscito]

Thanks all, I will plan on getting the oil tested and watch the trend until I find an interval I am comfortable with. Who does everyone suggest for testing?

I did check the magnetic plug and there was very minimal metal, also cut the filter (I have the tool), even after its open it is quite a mess in my experience to get the paper out. I used a razor blade. Any better methods? Also whats the best way to squeeze out the extra oil/dry the paper? I did it by hand as best I could but Im seen some videos that they look to have a press tool.

[DesertFox4]

Joe, just spread out the oil filter’s pleated material on paper shop towels over night on your bench and let gravity do the dirty work. Of course lay the pleated filter material upright so as not to lose the debris collected in the pleats.

[jiott]

I use the Metal Check by Aviation Labs kit sold by ACS, Spencer, etc. Its about $23 and includes prepaid shipping and lab analysis. You get the results back by email and they keep all your previous tests as an historical record.

I use a utility knife to cut the filter paper loose from the metal. Then I just pull it open in bright sunlight and it is easy to see the bright metal particles if any. Some guys wash it down with gasoline and filter it thru a white coffee filter to see all the debris. This is probably a very good method, but is not really necessary in my opinion.