Iron in oil analysis; how high is too high?

AeroLudite

Pre-takeoff checklist
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AeroLudite
Looking for insight from those with experience.

I have a Cherokee 140 with O320-E2A Lycoming with 1560hrs SMOH.
It’s had more or less regular oil analysis.
During past 24mos (250hrs) it’s been showing a climbing iron level.
67,88,94, 111,115, with reports being “flagged”. Last analysis came in at 97, and was “green lighted”.

Im curious as to whether these levels are cause for alarm, or just need “watching”, or just normal for an aging engine? I’ve been in alarm mode and pricing and sourcing potential overhaul.
 
What company is doing the oil analysis?
What's the interval between flights? 250 hours in 24 months means the plane is fairly active. Does it make static power?
What oil do you use and any additives?
Have the lead levels be climbing as well? Any other values of concern?
It would help to normalize your values to 50 hours. For example if 67ppm was in 45 hours and 94 ppm was in 65 hours, the values would normalize to 74 and 72. Normalization is important to be able to compare apples to apples.

Normalize thusly: N = (P/H)* 50, where P=ppm, H=hours, and N is the normalized value.

If, after reevaluating after normalization, you don't like what you see, I'd suggest a compression check and cylinder borescope.

Feel free to post the actual report.
 
Lycoming SI-1492D excerpt:

If an oil analysis report indicates elevated levels of aluminum (above 30 parts per million for non- turbocharged engines; above 40 parts per million for turbocharged engines) or iron (above 100 parts per million for non-turbocharged engines; above 130 parts per million for turbocharged engines), contact a technical representative at the Lycoming Factory Product Support Department.

3. If in a continuing program of oil analysis, results show a trend toward an increase in aluminum or iron content, inspect contents of the oil filter and suction screen in accordance with the procedures in Part I, Oil Filter/Suction Screen Inspection.

https://www.lycoming.com/sites/default/files/Piston Pin Plug Wear Inspection.pdf
 
Testing started (records I have) around 2013, ~900hrs in service).
Continuous past 6 analysis were by AOA. one by Aviation 1. Prior were AOA.

Lead levels are low., aluminum levels are low. Silicates are very low.
Everything is good but Iron.

previous owners used Champion filters and AeroShell 15w-50. BUT trend started before I switched to 100plus.
Starting November 2019, I began using AeroShell 100+ on recommendation of my a&p IA.
Most recent oil change (after most recent analysis) I switched back to 15w-50, and added CamGuard to see if that positively improves iron.
No metal has been found in screen or filters. We’ve even run a magnet over/on the filter element trying to find particles/ filings. NONE.
Engine is running VERY smooth, and develops top end of nominal static rpm’s (2,550). Standard pitch prop. Compressions mid ‘70’s.
Oh, meant to mention it has 3 chrome cylinders, one new Lycoming cylinder installed 2016. Has ~350hrs on it.

thanks for replying!

btw; no heat’s recommendation is exactly what AOA said after green checking tha last oil analysis. Test periods have been 27 to 54hrs. AOA standardizes the levels to 50hrs (I presume as they ask for hours and oil quantities.

further added; it’s my hope that it’s the rings on the three chrome cylinders as I want to STC it to 160hp. But normal chrome levels appear to negate that. Most likely source is cam/lifters....sigh!
 
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Adding Camguard will initially increase the metals found in the analysis as it cleans the engine out. Was it being used in the past or is this the first time it has been used?
 
111=115
94=97 and maybe even 88

Do you note the higher iron when there have been longer periods of inactivity (are you located in an area with poor winter flying weather or even stormy springs)? The working hypothesis is light cylinder corrosion that causes greater friction by the rings, thus more wear metals from cyl & rings.

I send my oil to Blackstone and they provide written opinions on trends, along with your averages as well as universal averages. If you email or call them, they ask questions that can help them identify a possible cause. Great customer interaction.
 
Also, adding Camguard to A/S W15W50 is not recommended by a Shell R&D guy I spoke with at OSH 2019.
 
Wear metal analysis is not a condition monitoring tool. Absolute numbers are pretty much meaningless by themselves. Rather, it is a trend monitoring tool. Large and consistent increases in wear metals MAY indicate a potential future problem. And you have to temper the numbers you are seeing with a little bit of slop, as there is going to be sampling error (non-representative sample depending on exactly how it is collected, non-linear wear with time, etc.), and measurement error. Atomic absorption methods are typically going to have at least 2-5% measurement error. At best, persistent, upward trends in wear metal analysis should be treated as an alert to closely monitor other evidence of engine wear. I did my own ICP-OES wear metal analysis for many years. (Actually my students did this for me on samples I provided.) I never found the information terribly illuminating, even when my engine was giving me clues of issues, like increased oil consumption. The only time it provided a really clear clue was when I saw a large and sudden increase in silicon. Turned out my air filter was not functioning properly.
 
I would NOT assume AOA normalizes its reported values until you verify with tech support. Blackstone, who also asks for hours and makeup oil does not normalize.
 
Adding Camguard will initially increase the metals found in the analysis as it cleans the engine out. Was it being used in the past or is this the first time it has been used?
Is this pretty universally true? I just got my first oil sample analysis back after switching from 15W-50 to W100 + Camguard. The metal numbers were way up on both engines. This oil change was done during the annual so compression checks, borescope, etc. were all done with nothing significant found. I'm hoping it's just the Camguard doing its thing.
 
Is this pretty universally true? I just got my first oil sample analysis back after switching from 15W-50 to W100 + Camguard. The metal numbers were way up on both engines. This oil change was done during the annual so compression checks, borescope, etc. were all done with nothing significant found. I'm hoping it's just the Camguard doing its thing.

It must be common enough that the company (ASL) has stated that will happen. I’d continue to run it and see what happens in your analysis in the next couple samples.
 
Is this pretty universally true? .., I'm hoping it's just the Camguard doing its thing.

Camguard doesn’t etch anything off your engine surfaces.

It mainly does three things: it coats surfaces, to an extent, with anti-corrosion ingredients when parked, and coats them with anti-wear ingredients when flying. And it inhibits sludge from settling on surfaces.

https://aslcamguard.com/technical-videos/

You can call ASL to ask about it. Their number is in their web page.

The anti-corrosion ingredients should help a little, in keeping iron levels down, but what’s much more effective is flying that is regular and frequent.

Since both engines did this, were you inactive? Did you park the plane where there’s lots of humidity?
 
Camguard doesn’t etch anything off your engine surfaces.

That wasn’t implied. What camguard will do is clean out an engine that has been run for a while prior to using the product. In other words, it will clean out the oil pan and all the little crevices where deposits sat previously.

As I mentioned in my last post, it is a common enough occurrence that the company states that initial oil samples will show high metals then settle down.
 
Is this pretty universally true? I just got my first oil sample analysis back after switching from 15W-50 to W100 + Camguard. The metal numbers were way up on both engines. This oil change was done during the annual so compression checks, borescope, etc. were all done with nothing significant found. I'm hoping it's just the Camguard doing its thing.

Which metal numbers went up? Some metallic elements are in the compounds and formulation itself.
 
Since both engines did this, were you inactive? Did you park the plane where there’s lots of humidity?
Ground-running it without flying it has a far bigger impact on corrosion than the environment. A cold engine gets lots of blowby into the case, and that blowby includes a lot of water vapor. Flying it closes the clearances and burns the stuff out of the case.
 
The technique used by the mechanic to take the oil sample is a big deal. If he pulls the plug and catches some of the first stuff to run out, he gets considerable sludge off the inside bottom of the pan around the drain hole. If he waits until it's nearly finished draining, the last oil is pulling more sludge toward the hole. The sample should be taken midstream. Sludge contains a lot of stuff that will mess up the analysis numbers.
 
CC2802.JPG

We use a vacuum pump to pull the sample oil into the jar that screws on to pump.
 
Camguard doesn’t etch anything off your engine surfaces.

It mainly does three things: it coats surfaces, to an extent, with anti-corrosion ingredients when parked, and coats them with anti-wear ingredients when flying. And it inhibits sludge from settling on surfaces.

https://aslcamguard.com/technical-videos/

You can call ASL to ask about it. Their number is in their web page.

The anti-corrosion ingredients should help a little, in keeping iron levels down, but what’s much more effective is flying that is regular and frequent.

Since both engines did this, were you inactive? Did you park the plane where there’s lots of humidity?
Not really inactive. I bought the plane in December and put about 75 hours on it through August when it went in for annual. Since the engine is turbo'd, I'm doing oil changes every 35 hours. I had the first oil change in February and this one in August, so about 35 hours in 6 months. The plane is in Phoenix, so humidity isn't an issue. I never just ground run it to warm the oil. I try to fly it at least every two weeks, even if it's just 40 minutes in the local area to run it and warm the oil. The only things that changed were going from 15W-50 to ASW100 and adding the Camguard.


Which metal numbers went up? Some metallic elements are in the compounds and formulation itself.
Aluminum, chrome, iron, molybdenum, copper and nickel.

Right Engine:
Right Engine Oil.jpg

Left Engine:
Left Engine Oil.jpg
 
engine at operating temp/warm. put tube down far enough to pick up oil
 
We use a vacuum pump to pull the sample oil into the jar that screws on to pump.
Just to add, you'll find drawing a sample from the top is a preferred method in certain circles whenever possible. It also will lead to more consistant readings. For example, a lot of sampling on the turbine side recommend top samples only. The pump above or the one recommended by Blackstone are very easy to use. But a disposible 60cc syringe/clear tubing can work as well depending on oil viscosity and is the way I would use in most cases.
 
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Sluggo, thanks for posting your Blackstone reports. That helps makes the situation easier to understand.

Blackstone is really good about giving well-calibrated advice.

If it were my engine, I'd do as they suggest: Borescope and compression tests now to check the cylinders for trauma, since you're seeing a combination of iron and aluminum. Resample in 20 hours (doesn't have to be a complete oil change, I suppose, but I would get the filter changed at that time to examine it for metal contaminants).

When you send in your next samples, in the comments box, you could remind them that both engines had changed a lot in the last sample, and mention whether or not metal was found in the filter, and how long was the longest period of inactivity. That might help them when they write their comments about your next sample.

I doubt if they will care much that you switched oil brands (in their experience brand of oil doesn't matter much). They can easily see in your data that you started using Camguard (lots of calcium now) and changed oil brand (phosphorous additive way down).

It might be worth checking how the mechanic is taking a sample. Maybe that changed, from one run to another. Blackstone's instructions emphasize taking the sample immediately after flying, while the oil is hot , although that's mostly to get rid of fuel and water - I'm not sure if it can affect wear metal concentrations. Blackstone's webpage instructions don't actually mention taking the sample mid-stream (after a count of ten, maybe), although every mechanic I've watched does so, to avoid settled solids and sludge.

It is really odd that both engines seemed to suddenly change the same way. But one sample isn't a lot, for detecting a change in trend.
 
Here's mine since the motor was new July 2020. The silicone numbers were way high at first from silicon valve cover gaskets I believe?
(edited)_IMG_1080.JPG
 
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Here's mine since the motor was new July 2020. The silicone numbers were way high at first from silicon valve cover gaskets I believe?
No. The gaskets are silicone; the stuff in the oil is silicon. Note the spelling. Silicone contains silicon, but not as the gritty sand we know as silicon. I have never heard of silicone gaskets driving up silicon levels in the oil. Those levels are driven by dust getting into the intake, normally. Or a dirty oil drain hose. Silicon in the oil is a bad deal; it grinds away at the engine parts. An inspection of your intake system might be in order. And a review of the oil sampling process.

From Wiki:

The term "silicone" is actually a misnomer. The suffix -one is used by chemists to denote a substance with a double-bonded atom of oxygen in its backbone. When first discovered, silicone was erroneously believed to have oxygen atoms bonded in this way. Technically correct term for the various silicone rubbers is polysiloxanes or polydimethylsiloxanes.[2]
 
No. The gaskets are silicone; the stuff in the oil is silicon. Note the spelling. Silicone contains silicon, but not as the gritty sand we know as silicon. I have never heard of silicone gaskets driving up silicon levels in the oil. Those levels are driven by dust getting into the intake, normally. Or a dirty oil drain hose. Silicon in the oil is a bad deal; it grinds away at the engine parts. An inspection of your intake system might be in order. And a review of the oil sampling process.

From Wiki:

The term "silicone" is actually a misnomer. The suffix -one is used by chemists to denote a substance with a double-bonded atom of oxygen in its backbone. When first discovered, silicone was erroneously believed to have oxygen atoms bonded in this way. Technically correct term for the various silicone rubbers is polysiloxanes or polydimethylsiloxanes.[2]

Thanks for the education.
The motor in question was new with a spotless airbox and fresh air filter.
It was suggested to me couple years ago that it would go down in time which it has.
I don't know anything for sure, kind of why I posted it.

"dirty drain hose"? never gave that much thought. Some times I run mineral spirits through it to clean it out. But not every time.

I will start doing it the same every time.
 
You can take a sample w/o the pump.

Insert the tubing and then put your thumb over the end and withdraw tubing.

2 or 3 reps should provide enough for a sample.

We used this method on fighters; with the engine running.
 
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