UOAs not what "we" thought?

[steved]

UOA - Usless Oil Analysis? - Bob Is The Oil Guy



This thread was interesting to me... what I have gotten out of recent reading at BITOG is the fact that a UOA is only that, a used oil analysis... it shows how well the oil is holding up, and has almost nothing to to with indicating engine wear!



And further, one UOA cannot be compared to another UOA (e. g. Conventional Oil UOA and a Synthetic Oil UOA) to show which one is providing better protection.



From what I've gathered, you can actually have a bad wearing engine with excellent UOAs... and that most wear can actually be from bad engineering and quality control of the engine's components, and not so much oil.



I thought this would be a good discussion topic because we (myself included) throw our UOAs up to show how well our engines are wearing, however we are only showing how well our oil is holding up.



steved

 

[Gary - K7GLD]

An interesting thread - I like this quote:

In some cases, Spectro analysis of oil will tell you important things about the performance of the oil and engine, and in some cases it will not. To say that Spectro analysis does not find a specific problem, and there for all spectro analysis is useless, is just plain silly. It would be akin to running out of gas when your gas gage is on 1/4, and then stating that gas gauges are useless. It sounds that you have read an email from a person that you trust (Roy at Redline) saying that UOAs are not useful for comparing the wear performance of different oils, and now you are scrambling to find other like statements, to bolster your belief. The fact is, no one measurement is the be all and end all of measurements. They have to be used in conjunction with other techniques. And yes, in some cases you can correlate UOA wear measurements to engine wear and/or problems, and thereby determine the relative merits of different oils. In some cases you can not. Just as in some cases, UOAs can be used to predict failure, and in others it cannot. Chrysler engine test engineers have a very nice SAE paper on just this subject and justified the expense of real time UOAs on engines during dyno testing.

YUP - don't toss the baby out with the bathwater - cover your bases as much as reasonably possible. That's why I include particle counts in my analysis - as well as bypass filtration and strong magnets directly in the lubricant flow path!

 

[steved]

An interesting thread - I like this quote:







YUP - don't toss the baby out with the bathwater - cover your bases as much as reasonably possible. That's why I include particle counts in my analysis - as well as bypass filtration and strong magnets directly in the lubricant flow path!

But the magnet and strong magnets are pulling particles out of suspension... and those particles (especially if stuck to a magnet) are probably wear particles, particles that wouldn't be seen in a UOA.



There was a guy who ran magnets and a 20w50 (I think), then dropped to a 0w20 (in the same engine). The UOA came back looking good on the 0w20, but the amount of metal captured by the magnet was a whole lot more than that caught with the 20w50.



My plan is to take a couple more UOAs on this CJ-4 now that I have good injectors, find an interval that works, and call it a day...



While all these "tests" are available, it would be cheaper to simply change the oil every 3k and not worry about it...



steved

 

[Gary - K7GLD]

But the magnet and strong magnets are pulling particles out of suspension... and those particles (especially if stuck to a magnet) are probably wear particles, particles that wouldn't be seen in a UOA.



Perhaps - but they WILL show on the magnets, and on the top surface of my TP filter - and after all, isn't that BETTER than leaving them to constantly circulate thru the lube flow - adding to the damage to internal components?



There was a guy who ran magnets and a 20w50 (I think), then dropped to a 0w20 (in the same engine). The UOA came back looking good on the 0w20, but the amount of metal captured by the magnet was a whole lot more than that caught with the 20w50.



EXACTLY! he was able to VISUALLY monitor wht was going on inside the engine regardless of what the analysis report said!



My plan is to take a couple more UOAs on this CJ-4 now that I have good injectors, find an interval that works, and call it a day...



While all these "tests" are available, it would be cheaper to simply change the oil every 3k and not worry about it...



AH - in other words, rather than use that innacurate fuel gauge as quoted in the earlier quote, its "better" to simply totally ignore it, and just constantly stop to top off the tank? :-laf:-laf



steved

While the use of oil analysis may not be the absolute, or final wear indicator - or comparison of anti-wear capabilities in different lubricants, it is DERN sure better than tightly closing our eyes and totally ignoring the issue!

 

[JFaughn]

Does it seem like if we dig a little bit that everything is bad / doesn't work / is a scam , ect .
I've been using oil analysis for some time & a few different companies , but I would say that I have not done long enough or with enough different engs / fleets to know either way , but I have been in the auto repair buis & hearing from other for most of my 50+yrs that it does have value .
I guess my point is that its a general cultural attitude the few yrs that , chicken little is ruling .
Rant over .

 

[JFaughn]

I was hoping to see more about this .
My analysis is down to about $10 from Cummins including the TBN , so not losing much .

 

[steved]

My whole point was the fact that *we* typically use UOAs to place a value on engine wear.

And according to others, that is not correct. If the particles are shedding in larger pieces than get analyzed, then you could have a UOA with levels of wear metals that are "normal" and have an engine that is wearing (as shown in the example with the magnet).

I just think some of us (myself included) used the UOA values to show "my low wearing engine" when in fact it is only really showing the oil's condition and what little bit of wear metals might have been suspended in the oil... but not the entire picture.

I don't think they are useless, just that we need to understand what they represent... instead of "my low wearing engine", they show "my well wearing oil". In the scheme of things, if you have an oil that is providing good UOAs, you probably can assume that would hopefully result in longer engine life, and on the other side you could probably that an oil giving poor UOAs is probably accelerating wear.

steved

 

[Cattletrkr]

I look at it this way. The UOA might not mean my engine is fine, but if the results come back with bells and whistles I've got something to start from.

A "clean" sample might not mean everything is OK, but a "dirty" sample usually means something is wrong.