Good Oil Analysis = Bad Oil

[BigAl]

OK, you folks have convinced me that dark oil equals good oil. It only means that the detergent additive package is doing its job in keeping the bad stuff in suspension so it doesn't form sludge.

If I get an oil analysis that shows low wear metals and low insolubles, that's bad. It means that the oil is not working right and that those elements normally present in used oil are probably locked in some sludgy engine deposit. I should look for oil that shows higher metals and insolubles to indicate that it has better dispersant properties.

The oils that we have been choosing because they don't seem to carry as much crud to the analysis shop are probably making our engines filthy.

Think about it.

Al

 

[Pablo]

I believe you are trying to condense a complex subject into a direct relationship. IMHO, it's just not that simple.

An easy debunk would just be: You could have a filthy engine, filthy looking oil and a terrible UOA. OR a perfectly clean engine, clean looking oil and very excellent UOA.

 

[Blue99]

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If I get an oil analysis that shows low wear metals and low insolubles, that's bad. It means that the oil is not working right and that those elements normally present in used oil are probably locked in some sludgy engine deposit. I should look for oil that shows higher metals and insolubles to indicate that it has better dispersant properties.

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Ahh, I'm having a little trouble reading this...

Are you being sarcastic or are you asking if this is a valid point to consider?

 

[tripleM]

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The oils that we have been choosing because they don't seem to carry as much crud to the analysis shop are probably making our engines filthy.

Think about it.

Al

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Going by your logic, my used oil analysis below would say that the PP is doing its job:
Good PP Bad used oil analysis on young engine

However, like prev. poster said: too many variables.

 

[oilyriser]

Keeping an eye on the metal parts of the engine is important. If the place where the oil filter mounts starts to turn brown, you have engine cooties and should take action.

 

[blupupher]

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If I get an oil analysis that shows low wear metals and low insolubles, that's bad. It means that the oil is not working right and that those elements normally present in used oil are probably locked in some sludgy engine deposit.

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Or it means your engine is not "shedding" (or whatever you want to call it) any metals, so the oil is doing it's job of protecting the engine. Dirty oil is usually from the by-products of combustion from what I understand, so dirty oil and low wear metals is a good thing.

 

[BigAl]

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If I get an oil analysis that shows low wear metals and low insolubles, that's bad. It means that the oil is not working right and that those elements normally present in used oil are probably locked in some sludgy engine deposit. I should look for oil that shows higher metals and insolubles to indicate that it has better dispersant properties.

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Ahh, I'm having a little trouble reading this...

Are you being sarcastic or are you asking if this is a valid point to consider?

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I think it IS valid to consider. Oil analysis is based on the premise that what's in the oil represents what's going on inside the engine. All you can really see is how much stuff is suspended in the oil, not what's left behind. Bad detergent could certainly lead to good insoluble and metal readings.

 

[ekpolk]

The problem, Al, is that your postulated situation is only one possibility among many, and without more information, you really can't tell which. I can envision a simple 2x2 matrix with "clean oil - dirty oil" on one side, and "clean engine - dirty engine" on the other side. I can envision reasonably foreseeable situations existing on all four cells of that matrix.

 

[Steelhead]

many different deposits in used engine oil that are not present in new oil

combustion products such as carbon, unburned fuel, non combustible chemicals in gasoline, water, acids

wear metals: iron or aluminum from block cylinder wall, steel and moly from rings, tin-lead-copper-aluminum-silver from bearings

colorization of used oil is seldom measured or even tracked or recorded by most fleet maint. units on OTH fleets, construction and hvy duty equipment
particle count and particle size is an important parameter
used oil color is not

 

[Ron AKA]

Suggest the ideal would be dirty oil and low wear metals. Yes, I would be concerned about clean oil and low wear metals. High wear metals is a concern whether the oil is clean or dirty. Not sure it is any more complicated than that.

 

[Blue99]

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All you can really see is how much stuff is suspended in the oil, not what's left behind.

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I agree with you 100%. Oil analysis reports are only showing the metallic elements, reported in ppm, contained in the oil drained/sampled from the engine.

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Bad detergent could certainly lead to good insoluble and metal readings.

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I think the good people at Blackstone would have problems with this statement, because, quite frankly, they've never prepared an analysis for an oil sample with bad detergent levels.

Low TBN, high insoluables, and usually higher mileage for the OCI, is the normal condition for the samples that they review.

Wear metals tend to not show up as a linear rate over the length of an OCI.

And I suscribe to the theory that the new oil is releasing wear metals from the previous OCI, over several hundred miles, that are caught up in the additive chemistry on the surfaces of engine parts and collected on any carbon/resin deposits in the engine.

So, no, I've never seen any evidence that, say, an SB oil with some anti-wear angents, and no detergents, would produce low wear metal used oil analysis.

My view is that the oil stream would still carry significant amounts of the normal wear metals, aluminum, copper, tin, iron and lead.

Oterwise, oil analysis would not work on hydraulic oil systems, as hydraulic oil does not utilize the detergent levels found in a motor oil.

 

[JohnBrowning]

No,No,No!!! You can have oil that is so black that it looks like roofing tar and still have a good UOA. Color does not mean anything!!! Some vechiles do not put that much junk into the oil to begin with. WHile other vechiles ________ all over themselfs constantly no matter what oil you run. Some vechiles need repair. A bad UOA is a bad UOA and may nothave anything to do with the oil or everything to do with the oil. You are trying to make a blanket statement about something that is rather variable and complex.

 

[BigAl]

Well, I thought this might generate some good discussion.

How about this for an example: FormulaShell is the bargain oil in the SOPUS family, but lately it has been generating some better UOA reports than its more expensive siblings.

Could it be actually causing less engine wear? . . . or . . . Is it because of a (possibly) weaker detergent package, that a lot of the contaminants never actually reach the drain plug?

 

[Spector]

After being an avid fan of UOA for 10 plus years I have had a complete turn around. Having seen terrible metal wear on my engines as well as great wear numbers in the long run none of them made any difference in longevity. todays engines are not going to die a premature death from high metal wear numbers etc. they will from lack of a decent OCi and coolant leaks etc but high metal numbers, maybe at 200,000 miles or more but doing UOA to look at wear numbers is, IMO a waste of time and money. took me a long time and too much money to the labs to come to this realization. I still do the UOA but rarely and for a unique reason, not on a consistent basis anymore. too subjective, an art not a science IMO. A good trusted mechanic is more reliable then UOA.

 

[BigAl]

I've changed my mind again . . . Now I realize that looking at a used oil analysis to determine oil quality is like visiting a sewage treatment plant to determine drinking water quality . . . Too much . . . errrrr . . . stuff . . . happens in between.

From now on, I will only use oils that have undergone rigorous laboratory and engine tests. Wait a minute! That would be anything with the API Starburst symbol. Wow, that simplifies things . . . .

 

[427Z06]

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From now on, I will only use oils that have undergone rigorous laboratory and engine tests. Wait a minute! That would be anything with the API Starburst symbol. Wow, that simplifies things . . . .

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That's one approach.

Here is a summary of tests GF-4/SM oils have to pass:

http://www.infineum.com/information/api-passenger-sm-2004.html

And one company has the balls to publish their results (see page 4):

http://www.schaefferoil.com/datapdf/701.pdf

 

[BigAl]

Good links! Schaeffer seems to pass by a mile. If others posted their data it would mean a lot more though. We can guess whether they are better or worse, but without numbers it would only be a guess. Even if they barely pass, they are still pretty good compared to oils of even just a few years back.

SM = satisfied mind