Please help me understand UOA

[demarpaint]

As I read through a lot of used oil analysis learning how to understand them, I have a few questions. Some of them were answered by searching, but the function is a little weak.

It seems Iron is always one of the things they seems to raise question and discussion, and started a lot of discussion about Mobil 1 5w30.

My question is this, would someone who uses a filter magnet get a false iron reading since the iron is trapped in the filter by the magnet? The wear is still occurring only you'd be getting a false reading?

Do some compaines add certain agents or metals into their blends for added benefits, but give a false reading? I read somewhere a company had iron in the mix. At least that is what they claimed and told concerned parties not to worry about the Fe reading in a used oil analysis, that a higher Fe reading was to be expected because it was part of the blend.


Frank D

 

[va3ux]

Originally Posted By: demarpaint
It seems Iron is always one of the things they seems to raise question .....

My question is this, would someone who uses a filter magnet get a false iron reading since the iron is trapped in the filter by the magnet? The wear is still occuring only you'd be getting a false reading?

In theory - yes. And perhaps in practice too. Your thinking is correct : if a contaminant is removed or partially removed by a magnet or perhaps a Bypass Filter, the level of that contaminant is reduced in the oil and in the used oil analysis. And that could cause failure to detect a problem. In fact I think this problem has happened : I've seen a few extended OCI used oil analysis from vehicles with tissue paper bypass filters, and the used oil analysis look outstanding. All the wear metals are low ! I suspect they were low because of the bypass filter, not because of superior oil performance.
Quote:
Do some compaines add certain agents or metals into their blends for added benefits, but give a false reading? I read somewhere a company had iron in the mix. At least that is what they claimed and told concerned parties not to worry about the Fe reading in a used oil analysis, that a higher Fe reading was to be expected because it was part of the blend.


I know that sodium has been used in the additives by some companies, and that can result in a false diagnosis of coolant leakage in a used oil analysis. We have seen some VOAs with several ppm of iron, but not huge amounts as I recall. I don't think iron is specifically part of any additive chemistry. But a few ppm could be present just from the piping in the blending plant. Certain synthetic oil/basestocks can give a false positive for Glycol but I don't remember the details.

 

[demarpaint]

Thanks. So my thinking is somewhat correct. An oil can get credit for being great in reducing wear and all along the wear metals are caught up in a good filter system or Fe trapped by a magnet. The only way to show true wear and how good an oil is would be to use a regular filter and no magnet, no bi-pass system.

Then are we really reducing engine wear by using a bi-pass filter and/or a magnet, or just showing better results but the wear is exactly the same? One tough thing to prove or disprove.

Frank D

 

[blackdiamond]

The purpose of the filter is to remove the wear particles, that are large enough to be filtered, so that they don't continue to cause wear. I guess any oil going through an Amsoil filter should look better on a used oil analysis.

I think a used oil analysis is best compared to other used oil analysis on the same car with the same filters, but I suspect the majority of the used oil analysis particles are small enough to go through most filters.

 

[LargeCarManX2]

Wear metals are identified by an analysis and are expressed in parts per million. They are usually in the 3-8 micron range. I would not think a filter would throw off any numbers of the spectrochemical analysis!

 

[demarpaint]

Would a magnet throw off an analysis?

Frank D

 

[LargeCarManX2]

I would say No! any experts out there really know?

 

[demarpaint]

I would think it would have to lower the iron reading. Even though the iron is still wearing at a higher rate than indicated by the analysis.

Frank D

 

[JAG]

http://www.filtermag.com/tech.php#oilanalysis
Quote:
Oil Analysis Test

Attached is a series of tests on one report. Predictive Maintenance Services performed the independent tests. The oil samples were taken on a 2002 Chevy with a Diesel Engine that has a Harvard Bypass System.

Test # 88532, 88069, 79299 was WITHOUT a FilterMAG™ placed on the filter. Test #95049 was performed WITH the FilterMAG™ in place on the filter.

While the spectro Fe (iron) stayed essentially the same, if you look at the graphic in the center you will see a huge drop in the particle count (350 on test #88532, only 58 on #95049). The symbol >2 and >5 refer to particle sizes, 2 micron and 5 micron respectively.

So these test results say not to expect at least some magnets to reduce the measured iron wear in a engine oil UOA despite it taking iron out of the oil. It's that particle size thing I often bring up with used oil analysis. I have personally verified that the FilteMag magnets really works. It grabs a hold of a lot of decently sized ferrous particles that would not be measured to a significant degree by a spectrographic used oil analysis.

 

[Spector]

Myself included I over analyzed everything for years on the UOA A binder full of results) and did some testing of my own and basically evolved into my current oil change policies.
First, it makes no difference what oil filter you use (well, except for fram IMO) as none of them really make any difference on a well maintained engine. The UOA are basically the same and this is true if you change the filter half way through or go the distance ( in my case 12,000 miles when I tested this theory)

Second, use a quality oil (if you use synthetic you must stretch the OCI to at least 7500 to make it cost effective.

third, air filtration is of upmost importance and regular maintenance as suggested by the owners manual as well as to belts, fluids, etc etc.

Forth, stay away from additives, for the MOST part they are snake oil and not needed

Save your money and avoid UOA, they are great for creating worry ( and cost the same as an oil change) when in reality, very little can be done to alter an engines wear (assuming a well operating engine to begin with, no coolant leaks etc). Todays engines with todays oils will easily go 200,000 miles with regular maintenance and reasonable OCIs

 

[demarpaint]

Well said Spector! I was trying to understand the used oil analysis and its value. It would help trace a bad filtration system, or coolant entering the oil. It might also tell you what oil is working best in your engine, but that could change with a new batch of oil from the same company. So do we really know for sure each time we change our oil even if we use the same oil? What I have noticed is there are some brands that seem to show better results and based on those results it might be a good idea to use that brand oil vs one that consistanly shows higher wear #'s. Those are the compaines I want to give my $ to.


We all know engines wear out, what I am finding is things like a good filter or magnet isn't going to stop or even slow down the wear that is occurring. What a good filter or magnet might do is stop some scoring of small metal particles that slipped past the filter, the wear is still there and still occurring.

Frank D