Oil Analysis - New aircraft owner, first oil change soon

CC268

CC268

Final Approach
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CC268
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Hey guys,

I have 1965 Cherokee 140 - has about 1250 hours on it, but it runs so damn good! I got my first oil change coming up in about 15 hours. I think oil analysis is probabaly a smart thing to do at every oil change. Is there a recommended kit, company, etc to do this with?

Thanks.
 
Use the same kit every time and keep the report. It is interesting. But really, compressions and oil usage tell the story in most cases. I suppose if you see a dramatic increase youre going to want to investigate, but you usually see something in your oil filter if that happens. You can do it if you want.
 
:yeahthat: Always keep the reports. The oil analysis will give you the best insight of the engines' health. When metal starts to appear, overhaul will follow soon after.
 
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Those reports always show some metal. It's an dramatic INCREASE in metal that causes alarm.
 
coloradobluesky said:
Those reports always show some metal. It's an dramatic INCREASE in metal that causes alarm.
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It should only just be tracings if there is any. Significant hairlike ferrous metals that appear would cause some concern for me.
 
Iron, aluminum, copper, lead and other metals are reported in parts per million. In a normal engine, there is a gradual increase as the engine ages. In some engines, not GA engines but jets and turbines, there are bands of metal that are indicators. As in "when it starts reporting titanium, bearing A100L is in need of replacement" (because it is worn down to that band of titanium (or whatever) indicator). I think they just burn the sample in a mass spectrometer, or some similar setup.

"Hair like ferrous metals" sounds more like something you would find in an oil filter.

The problem is, when does it become significant. The reports I saw didnt say. Maybe some do. Would be nice feature if they graphed the current report with the previous reports showing trends in graphical form.
 
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Along with watching metal trends keep an eye on silicon since it is an induction leak indicator.
 
There will always be metals, I was told when I did my first sample on my plane they wanted to see Iron ppm less than the hours on that sample. Ive got a good trend going on now and the last oil change my iron spiked. They flagged it and said keep doing what im doing and re test at my normal interval. Hopefully it doesn't stay elevated or ill be gearing up for an OH.
 
Remeber all you're doing is finding your base line and looking for changes from that, I'd also pay close attention to your normal temps, pressures and fuel flows and IAS at cruise settings, and cut your oil filters, keep a eye out for changes and remeber "in the green" isn't good enough, every plane has it's happy place and any thing diffrent from that should be looked into, airplane ownership isn't too bad if you nip things in the bud.
 
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