What Does a UOA Really Tell Us?

[Gary Allan]

Well, Caddyman ..suppose I don't want to do 3-4k oil changes? Suppose I want to do 15k oil changes? Suppose I own one of the various engines that have composite intakes that are prone to leaking coolant into my oil? Suppose I don't care if the engine lasts for 20 years ..but I'm going to put 20 years worth of mileage on it in 10 and don't want a career in visiting Jiffy Lube ..or buying a waste oil burner for my garage?? Suppose I want to max my fuel economy with a light weight neo 20 weight and want to know if it can cut it over my needs for extended drains?

What should I do, consult a Tarot cards for this information?

 

[ekpolk]

quote:

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Originally posted by Caddyman:
Reciprocating piston engines start destroying themselves the moment they are first started. The ones used in automobiles have a very short life expectancy compared to aircraft or stationary engines. Why build a 20 year engine for a comsumer product that will be wrecked or rust away in 10 or 15 years? The engine is probably the longest lasting part of the car...

Sure, you can watch the process happen and obsess over it with a used oil analysis, but why bother? Use whatever oil is recommended in the owners manual, change it every 3000-4000 miles and don't worry about what is in that black mess you dumped in the used oil collection tank...

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Ahem, then I really have to wonder: why did you bother joining a forum like this????

Oh yeah, can you PM me your real identity -- I want to make sure I add you to my list of folks from whom I'll never buy a used car. . .

Seriously though, your comment applies to any man-made machine. They all start destroying themselves the moment they are put into service. So what's wrong with doing your best to extend that service life? Are all those trucking outfits and airlines that use used oil analysis just dominated by maniacs with terminal OCD???

used oil analysis are not the be all and end all, but they do provide good information, especially when they are put in the proper context.

 

[GeorgeCLS]

Waaaait a minute! In my professional opinion UOA (simple spectro) is invaluable even for 3,000 to 4,000 mile oil drian intervals... The number 1 and 2 *serious* alerts by a wide margin (induction dirt and anti-freeze contamination) are NOT readily detectible and changing oil every 3,000 to 4,000 miles will not stop the early destruction of engine/components that dirt/anti-freeze will cause. A relatively inepensive Spectro used oil analysis is worth its weight in engine gold, again, from my professional experience. I review between 200 to 300 oil analysis a day and spectro used oil analysis prevents millions of dollars of avoided engine/component failures.
My discussion of particle count/ferrography was relative to comparison of wear rates for lubricant comparison, etc.. As Terry indicated, PC/Ferrography are much more costly but relatively inexpensive when one is looking at a lubricant performance as they provide a complete picture of what is taking place...
Again, spectro is the relative bargain of the century for normal preventive maintenance and life extension...
George Morrison, STLE CLS

 

[buster]

quote:

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My discussion of particle count/ferrography was relative to comparison of wear rates for lubricant comparison, etc..

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Seems Redline feels this way too. I guess it's really tough to determine what is wear and what isn't and also the particle size unless more expensive tests are run as George/Terry indicated above. Coolant leaks, viscosity and TBN are what I like to look at. Now if Pb is 28ppm on 3 samples with one oil and then drops to 10ppm with another 3 samples with another.

 

[Shannow]

With the particle counts that Stinky Peterson showed us in the VOA section, do engines (i mean oil filters) typically clean up what the manufacturer didn't or go from apalling to worse ?

 

[GeorgeCLS]

Re: "do engines (i mean oil filters) typically clean up what the manufacturer didn't or go from apalling to worse ?)
Frankly unless one gets into serious by-pass filtration, over the shelf oil filters do nothing but capture bricks and birds, relatively.. The Mobil 1 filters do a better job but given the gamut of oils available, it is very difficult for standard spin on filters to be too fine in that cold weather flow and dirt holding capacities are greatly compromised with some oils (mineral based, as example)..
So, no, standard spin on filters do not do much filtration below 20 microns so used oil analysis is very effective in reporting contaminant/wear levels..
Even in serious off-line filtration, sub-micronic particles still get pretty much a free ride so spectrographic analysis is still very effective as an analytical tool.
George Morrison

 

[jsharp]

quote:

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Originally posted by Caddyman:
Reciprocating piston engines start destroying themselves the moment they are first started. The ones used in automobiles have a very short life expectancy compared to aircraft or stationary engines. Why build a 20 year engine for a comsumer product that will be wrecked or rust away in 10 or 15 years? The engine is probably the longest lasting part of the car...

Sure, you can watch the process happen and obsess over it with a used oil analysis, but why bother? Use whatever oil is recommended in the owners manual, change it every 3000-4000 miles and don't worry about what is in that black mess you dumped in the used oil collection tank...

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You might want to check the numbers again on aircraft engines. How many hours between required major overhauls on a common air cooled boxer layout light aircraft engine? Compare that to an automotive engine that most of us expect to run 200,000 miles before being opened up. That's a lot more than 1000-2000 hours and the automotive engines are expected to be used in worse conditions with far less care and still cost a fraction as much...

 

[1sttruck]

From what I could figure out a used oil analysis is primarily useful for determining if an oil is still suitable for use. There appears to be too much still not known about interactions between different oils, anti-wear films, different engines, etc., to use the used oil analysis that we typically see in this forum to determine 'how much better one oil is than another' by the amount of wear metals in the analysis. Wear is differnt than oil condition, and although it initially seems obvious that wear metals in oils is a good measure of wear, observations like 'old oil is better than fresh oil as determined by used oil analysis' suggest otherwise. It seems that in a number of cases we're measuring the disruption of anti-wear films instead of wear.

 

[Gary Allan]

quote:

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It seems that in a number of cases we're measuring the disruption of anti-wear films instead of wear.

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I think this is the case with many of the RL used oil analysis. It appears to be more of a displacement and exchange of material instead of production of it.

Still many unanswered questions on this process. Why between 2-3k (as most data suggests)??

Why the removal of this protective layer ..every time? I still find it hard to believe that no one ..apparently worldwide, has published the "fat" on this.

Maybe it's something like "petro-chemical correctness". Everyone knows what they want to say ...but feel it would be improper to do so.

 

[TheFuror]

quote:

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Originally posted by Gary Allan:


What should I do, consult a Tarot cards for this information?

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I could loan you a deck.

Bob W.

 

[TheFuror]

quote:

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Originally posted by ekpolk:
Ahem, then I really have to wonder: why did you bother joining a forum like this????

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'cuz it's a ton of fun and informative too.

What I like about BITOG is the wide variety of opinions and that we are all free to take it/leave it as we see fit.

Bob W.