Results Library
Got a question about something on your report? Find out more below.
Element or Test
Video
We look for antifreeze with potassium and sodium.
Those elements get left behind like a footprint when antifreeze gets into the oil (even if the oil gets hot and any actual moisture cooks off.)
You don’t want any antifreeze in the oil, of course, but most engines can tolerate a little bit, for a while at least. If you have a little coolant in the oil, shorter oil changes can help keep it from doing too much damage.
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In a gas or diesel engine, aluminum is usually from pistons, bearings, and the case (heads & blocks). It’s also from piston pin plugs in aircraft engines.
In a transmission or industrial samples, we find aluminum from the housing, oil pump, bearings, and gear & pump vanes, pistons, and valves.
Gas/Diesel Engine: Oil additive (detergent/dispersant additive, meant to keep things in suspension)
All others: Trace element
Gas/Diesel Engine: Oil additive
Aircraft: Should not be present in an aircraft oil sample. If it is, probably a non-ashless oil has been used.
Transmission, Differential, Transfer Case: Typically a trace element in steel alloys
Industrial: Usually a steel alloy but exact source is dependent on the system
Gas/Diesel Engine: Â Oil additive (detergent/dispersant additive) meant to hold things in suspension in the oil
Aircraft: CamGuard; other than that, calcium should not be present in an aircraft oil sample. If it is, probably a non-ashless oil has been used
Transmission, Industrial: Oil additive, trace element
Gas/Diesel Engine: Rings
Aircraft: Rings, some replacement cylinders, plating on exhaust valves
Transmission, Differential, Transfer Case: Typically a trace element in steel alloys
Industrial: Usually a steel alloy but exact source is dependent on the system
Gas/Diesel Engine: Bronze parts like bushings, oil coolers, and bearings (including maybe turbo bearings)
Aircraft: Bushings, rod & main bearings, exhaust valve guides in the O-200 and O-300, starter adaptor in Continentals, piston pin plugs in Lycomings, chemical reaction with the oil (Lycoming)
Transmission: Synchro or bushings, bearings, clutch plates, oil cooler oxides in some marine transmissions
Industrial: Bronze/brass parts, oxides
The flashpoint measures the temperature at which the vapors coming off the hot oil ignite.
All oils have a “should be” flashpoint. Any contamination will lower the flashpoint. In a gas or diesel engine, fuel usually lowers the flashpoint, but solvents (like engine cleaners) can do it too.
Unless you tell us you’ve used a solvent, we assume a low flashpoint is caused by fuel. We base our fuel calculation off the flashpoint reading.
The lowest amount of fuel we can measure is 0.5%. So we put <0.5% on the report to mean, basically, no fuel. It’s possible fuel is present at less than 0.5%, but if it is, we can’t see it. (And it’s inconsequential at that level anyway.)
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Insolubles are solids that are present in the oil. These solids form as a result of heat and use. Typically insolubles are a measure of how good a job the oil filter is doing.
Gas/Diesel Engine: Cylinders, camshaft, crankshaft (or any rotating shaft), valve train components like lifters and followers, connecting rods on any V-type engine
Motorcycles: Same as above, plus transmission shafts, gears, sometimes bearings
Aircraft: Cylinders, camshaft or any rotating shaft, valve train components, lifters and followers, oil pump, connecting rods, starter adaptor in Continentals (with copper), corrosion, gears
Transmission, Differential, Transfer Case: Steel parts like gears and shafts, roller bearings, possible clutch plate material
Industrial: Gears and other steel parts
The ISO Code, also known as a particle count, gives you a reading that represents the number of particles present in an oil sample in microns.
The results are estimated by a laser counter and will show the number of particles present at >4 micron in size, >6 micron in size, etc. up to >70 micron.
Gas and diesel engine oil is usually too dirty to do a PC on. This extra test is more suited to very clean oils, such as hydraulic oil.
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Gas/Diesel Engine: Bearings, leaded fuel, octane boosters
Aircraft: 100LL blow-by, bearings
Transmission: Synchro or bushings, bearings, clutch plates, oil cooler oxides in marine transmissions
Gas/Diesel Engine: Oil additive (detergent/dispersant additive, meant to hold things in suspension in the oil)
Aircraft: Trace element
Transmission, Industrial: trace element
Trace element; sometimes from fuel blow-by in gas and diesel engines
Gas/Diesel Engine: Typically an anti-wear additive
Aircraft: Piston scuffing in Continentals; otherwise it’s a trace element and should not be present in any significant quantity. If it is, probably a non-ashless oil has been used
Transmission, Industrial: Trace element
Gas/Diesel Engine: Usually a coating or part of a steel alloy. Infrequently from Nikasil cylinders, valve guides, cylinder wear in some motorcycle engines
Aircraft: Exhaust valve guides, nickel cylinders
Transmission, Differential, Transfer Case: Steel alloy, coating
Industrial: Steel alloy, coating
Oil additive
Gas/Diesel Engine: Typically a marker for antifreeze; can also be flux compound from a new emissions system (with aluminum); sometimes it’s from aftermarket additives
Dirt contamination; silicone products like sealers, gaskets, and lubes; sometimes from antifreeze (when potassium and sodium are also present); sometimes an oil additive
Gas/Diesel Engine: Bearings, turbo bearings, solder
Aircraft: Rod bearings in radial engines
Gas/Diesel Engine: Antifreeze, oil additive, sea water in marine engines
Aircraft: Antifreeze in a liquid-cooled engine, sodium-filled valves in big Lycoming engines
Transmission, Industrial: Trace element
The TAN (Total Acid Number) is a measure of the oil’s acidity level. Interestingly, not all oils start with a TAN of 0.0. Therefore it can be helpful to know the starting TAN of a virgin oil sample, so you can see how the TAN has changed while the oil was in use.
We consider a TAN to show low or normal acidity levels around 6 or less, and a fair amount of acidity at higher levels than that.
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TBN stands for Total Base Number. It’s a measure of how much active additive remains in the oil.
The TBN starts out strong, around 6-8 in gas engine oils, and 10-12 in diesel-use oils. The longer you run the oil, the lower the TBN drops. We consider the low threshold to be 2.0 or less.
The additives do not disappear from the oil as you run it. They are still there and you’ll see them listed in ppm on your report. But the longer you run the oil, the more the additives become inactive. Once they’re inactive, the additives are no longer neutralizing the acids that form from combustion and other factors.
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Gas/Diesel Engine: Bearings, sometimes an alloy in bronze or brass parts
Aircraft: Bronze parts, bearings, parts coating
Transmission:Â Synchro or bushings, bearings, clutch plates
Gas/Diesel Engine: Trace element, uncommon in most engines; used in the intake valves and connecting rods in the LS-7
Aircraft: Trace element
The unit/location averages show typical wear for your particular engine.
But wait! When Jim Stark started Blackstone, he was mostly focused on fleets. So he designed the unit/location column to reflect averages for that engine type by customer. In other words, if a fleet only had Detroit Series 60 diesels, the fleet manager could compare his fleet’s average wear to national (universal averages).
For most people, this distinction doesn’t matter. Most of us only have one F150, or one Subaru Outback, etc.
But for people with more than one of the same car with the same engine, or for an FBO that sends us samples from many planes with the same engine type (all IO-550s, for example), the unit averages will be a fleet average. If you have more than one BMW with an S65 engine, the unit averages will show typical wear for the “mini-fleet” you have in your garage.
The unit averages can be helpful in determining what’s normal for your particular engine. Not all engines look like universal averages. They’re only averages, after all. If you live in a bit city and are sitting in traffic a lot, or you’re racing, or you idle a lot, or do a lot of mountain driving…all those things can cause your engine to wear differently than most. And that’s fine! As with universal averages, we really just want to see steady trends develop.
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The universal averages show typical wear for all the normal engines of that type that we’ve ever done.
They’re based on engine type, not the vehicle type, plane type, etc. So if Toyota uses a particular engine in several of their vehicles, universal averages will include everything the engine is used in.
In a gas or diesel engine, you are only comparing your wear metals and silicon to universal averages. You can’t compare the additives, because averages reflect a mix of all the different oil types people are using.
Not all engines wear like averages – a lot depends on how you operate the engine, how it’s stored, etc. If you drive it like you stole it, your wear metals will probably be higher than average, and that’s okay. If you change the oil a lot more often than most people do, you’ll likely have less metal than average.
Once you establish trends, we’ll rely less on universal averages and more on your own, unit/location averages and trends to tell us what’s normal for your particular engine.
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The viscosity is the measure of the grade, or the thickness, of the oil. If it started out as a 5W/30, or a 75W/90, or an ISO 320 oil – is it still that thickness after the oil has been used and exposed to heat?
We measure the viscosity in both SUS and cSt. That’s just two ways of measuring the same thing, like Fahrenheit and Celsius.
Generally we find water contamination with the crackle test. If the oil crackles or boils in the hot flashpoint cup, we will measure any water that separates out during the insolubles test.
We can also measure water in ppm using the Karl Fischer test. This is an extra test that you need to ask for when you send in the oil. This is a more exact method of measuring water.
Questions?
If you are looking for a test that’s not listed here or you’re looking for bulk pricing, please call us at 260/744-2380.
