bypass filter skewing oil analysis

[lazaro]

so I have been told my bypass filter is masking my accelerated wearing engine.
I was told the bypass filter is catching all the wear metals and not giving me a true indication of the condition of my engine.
is there any truth to this opinion?

 

[TimVipond]

If the wear metals are large enough to be captured by a bypass filter, I'd rather have them out of the oil. Not sure this is the case though.

 

[TimVipond]

According to this paper http://www.freepatentsonline.com/3981584.html , bypass filtration could skew the results. Anybody know if oil samples are filtered before wear metals are analyzed, and if so, the particle size analyzed?

Lots of people see metal particles on their full flow filters when they cut them open, and these range from 40 microns to 15 microns at 99% efficiency, so even full flow filters may skew the results.

 

[TimVipond]

It seems particle size analysis is useful in predicting engine wear. Seems like this should be done along with quantitative/qualitative analysis of the metals to be more useful. How much more does a particle size analysis add to the price of an oil analysis?

 

[Steve S]

Uoa's only see the little bits of wear metal.

 

[Bill Plock]

FERROGRAPHIC OIL ANALYSIS can pick up the big stuff spectrographic UOA's don't detect ...

 

[Gary Allan]

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Anybody know if oil samples are filtered before wear metals are analyzed, and if so, the particle size analyzed?

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Blackstone does not. I asked about this as I was comparing it to Atomic Absorption. They had some vacuum/stone filter thingie at my old job. Kristen said they don't filter it ..but their machinery only reads up to about 5um (or was it 15um

)

The guy who did the filter comparison on Jeepsunlimited (Frank= DalesII) had some lab that digested the samples. He had particles in the thousands. They added acid to reduce all the big chunks.

Although I do think that filtration may alter the UOA ..I don't think that it alters the indicators of issues. That is, even though you can't read a 15um particle, you can surely see the submicronic debris that it creates as it plays bumper cars with various surfaces in the engine.

I really don't think that it's of that great a magnitude anyway. Have you seen anyone say "Hmmm, you need to get more moly in your oil. You obviously have too many 15um particles floating around" That is, even if you knew that this was the case, what would you do to prevent it from happening ...as in the cause. Sure, you can filter the stuff out.

 

[boxcab]

According to the Oil Analyzers document G-2047, p.10, "the sizes of wear metal particles that can be identified by spectrochemical analysis are between 3 and 10 microns." This would suggest that a bypass filter such as the EaBP series that are 98% efficient to 2 microns might indeed reduce particle counts for wear metals. Of course, that's really what we want, isn't it, especially with soot?

 

[TimVipond]

Even the Amsoil EaO filter is 50% efficient at 7 microns, smack dab in the middle of the wear metals analyzed.

 

[Gary Allan]

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the sizes of wear metal particles that can be identified by spectrochemical analysis are between 3 and 10 microns.

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Then they cannot read to the particle level. That should not be right. In that case, if you have enough filtration ...you'll show ZERO wear metals.

 

[Terry]

lazaro, it can if the analyst or lab is stupid,disinterested,ignorant,using poor quality test equipment etc.

Most of standard ICP or AA spectro testing protocals will reveal (when properly interpreted) signs of problems even when larger particle detection or ferrography is not employed. It's why for our customers (professional or consumer level) we begin with our low cost Premium Service. The chance of a large chunk of material metal or not breaking off and the 10um or less level of spectral detection NOT seeing it is small.

Does Spectral analysis miss things, sure, however the total test result if using a broad battery of basic tests in addition to wear metals can alert the experienced analyst that odd results need to be explored further.

This is where science,service,and smarts cross and we care enough to provide that for every customer the best we can.

Terry

 

[Terry]

boxcab, as far a soot detection we use FTIR to determine soot levels analysis.

Our Premium test for $50 includes my personal interpretation the normal elementals for wear,contamination, organo metallic adds, and V40c,V100C,TAN,TBN,Flash(closed cup so its biased to the conservative), Karl Fischer water content in PPM, FTIR oxidation,nitration,glycol,fuel,Viscosity index and finally sulfate byproducts.

Thats a really high quality AND high quantity battery of tests not offered anywhere at this cost for automotive customers.

TD

 

[Terry]

There was a question somewhere in the filtering forums about filtering out add pack.

I rarely see that in automotive analysis no matter how efficient you think your bypass is!

However what I do see in aircraft, precision ( servo-valve) level hydraulics is 0.5 um filtering able to pull water derived depletion of the fluids adds from a multitude of problems.

1) decomposing additives, usually severe issues going on.
2) Polar adds attached to wear particles then filtered out.
3) additives condensing ( desolublize) into solid suspensions from cold temps.
4) contaminated or incompatible fluids forming solids.

MOST of the time these effects are MIS INTERPRETED by the analyst as add filtering when it is not the case.

Many "degreed,qualified,CLS, STLE engineers,techs, etc" make this mistake over and over.

 

[lazaro]

Quote:

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lazaro, it can if the analyst or lab is stupid,disinterested,ignorant,using poor quality test equipment etc.

Most of standard ICP or AA spectro testing protocals will reveal (when properly interpreted) signs of problems even when larger particle detection or ferrography is not employed. It's why for our customers (professional or consumer level) we begin with our low cost Premium Service. The chance of a large chunk of material metal or not breaking off and the 10um or less level of spectral detection NOT seeing it is small.

Does Spectral analysis miss things, sure, however the total test result if using a broad battery of basic tests in addition to wear metals can alert the experienced analyst that odd results need to be explored further.

This is where science,service,and smarts cross and we care enough to provide that for every customer the best we can.

Terry

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I am asking cause I was told that this sample http://www.voogru.com/images/oil2.jpg was skewed due to the bypass filter on my vehicle, and that the analasis was incorrect that the oil was not good for continued use.
of course I paid for the sample that came back good and I didn't pay for the opinion that told me my oil is bad and needs changing before certain doom. do I have anything to worry about? Im getting the best MPG from my vehicle I ever got in 8 years with this dirty ol oil...

 

[ConfederateTyrant]

Who told you that it was skewed?

 

[Gary Allan]

Quote:

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Quote:

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lazaro, it can if the analyst or lab is stupid,disinterested,ignorant,using poor quality test equipment etc.

Most of standard ICP or AA spectro testing protocals will reveal (when properly interpreted) signs of problems even when larger particle detection or ferrography is not employed. It's why for our customers (professional or consumer level) we begin with our low cost Premium Service. The chance of a large chunk of material metal or not breaking off and the 10um or less level of spectral detection NOT seeing it is small.

Does Spectral analysis miss things, sure, however the total test result if using a broad battery of basic tests in addition to wear metals can alert the experienced analyst that odd results need to be explored further.

This is where science,service,and smarts cross and we care enough to provide that for every customer the best we can.

Terry

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I am asking cause I was told that this sample http://www.voogru.com/images/oil2.jpg was skewed due to the bypass filter on my vehicle, and that the analasis was incorrect that the oil was not good for continued use.
of course I paid for the sample that came back good and I didn't pay for the opinion that told me my oil is bad and needs changing before certain doom. do I have anything to worry about? Im getting the best MPG from my vehicle I ever got in 8 years with this dirty ol oil...

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Let's think about this. Any UOA ..all of them ..tell you whether the oil is suitable for continued use. It's as simple as the TBN, visc, fuel content, flash point, insolubles. If all those are in good shape ..and your silicon is looking good ..then that OIL is good to go.

Now whether the oil is suitable for a given application, then it gets tricky. I would still somewhat disagree with bypass filtration skewing the results. Let me explain my take on it. The bypass filter is going to remove the bigger chunks to a fine level ..more so than the full flow filter. These missed chunks, which are from unknown origin, are going to result in more smaller particles being produced due to these larger items having a never ending pinball game going on. It would also be reasonable to expect that where ever a big particle dislodged from ..that there's now a leeching cavity that's being attacked by your AW package plating it out with all of its goodies.

Less larger particles to play pinball, less resultant wear markers. Not totally, but reduced. So you're not preventing particles that are going to be generating secondary wear markers ..but you're limiting their impact.

That's just my reasoning. It could be total bee-ess.