Predictive Maintenance Services, Inc.

How to read an Oil Analysis Report

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This analysis measures, in parts per million the quantity of wear, additive and contaminant metals. It is important to note that some metals may be present in any of the three categories.

IRON: Gears, bearings, rings, pistons, cylinders, shafts, valve train, other steel components, rust and other iron oxides.

CHROMIUM: Chromed parts such as rings, rolling element bearings. Also chromate which is sometimes an additive in coolant fluids.

LEAD: Usually from babbitt bearings. Sometimes an additive in gear lubes and as tetraethyl lead in leaded gasoline.

COPPER: Bearings, thrusts, bushings, clutch discs in some transmissions, bronze or brass. Additive in some oils. Heat exchangers.

TIN: Usually from babbitt bearings. Can also be piston wear.

ALUMINUM: Pistons, some bearings and bushings, housings, blowers. Also as alumina from dirt or grinding compounds.

NICKEL: Bearings, valves and valve guides, shafts.

SILVER: Bearings, silver solder. Also indicator of coolant-especially when glycol is indicated.

CADMIUM: Metal plating on some bearings. Also used in some paints, plastics and solders.

VANADIUM: Turbine components. Found in some marine fuels

SILICON: Primarily from dust and dirt. Also anti-foam additive in lubricants. May also be from seals or gasket materials in new or newly rebuilt engines.

BORON: Anti-oxidant in coolants and lubricants. Detergent/dispersant additive in some lubricants.

BARIUM: Corrosion and rust inhibitor, Detergent, Anti-wear and Extreme Pressure additive. Additive in some fuels.

SODIUM: Corrosion inhibitor in coolants and some lubricants. Can also be contamination in some environments (sea water).

MAGNESIUM: Primarily detergent/dispersant oil additive. Some housings or castings. Also increases alkalinity.

TITANIUM: Anti-wear additive. Wear metal in turbines, springs and some valves.

CALCIUM: Detergent, Dispersant, Anti-corrosion, Neutralizes acids.

PHOSPHORUS: Primarily extreme pressure additive. Corrosion inhibitor in some coolants. Combustion Deposit reducer in fuel.

ZINC: Primarily anti-wear and anti-oxidation additive in lubricants. Also a corrosion inhibitor. Increase alkalinity. Copper alloy wear (brass, bronze and galvanized components).

MOLYBDENUM: Extreme pressure and anti-oxidant additive, ring wear, coolant additive, grease additive.

MANGANESE: Shaft, bearing, valve and gear wear. Anti-knock additive in fuel. Oil additive.

LITHIUM: Grease soap. Contaminant when found in an oil sample.

ANTIMONY: Extreme pressure additive, anti-wear additive, oxidation inhibitor, rust & corrosion inhibitor.

POTASSIUM: Corrosion inhibitor in oils and coolants, Sea Water, Additive in some fuels.


WATER (VOL): Accurate to .05 and reported in volume. Can cause oil degradation, poor lubrication, rust and may emulsify in oil. Water may also affect the viscosity (thickness) of oil.

KARL FISCHER: Detects very small quantities of water in systems requiring more accurate results. Typically reported in parts per million.

GLYCOL: Indicates antifreeze (ethylene-glycol) in lubricant which can cause sludge,varnish and lubricant breakdown. Can attack bearings causing seizure. Reported as "N" Negative, "T" Trace (100-300 ppm),"M" Moderate (>500 ppm) and "E" Excessive (>1000 ppm).

FUEL: Indicates unburned fuel in the lubricant. Causes oil thinning, increased wear and reduced load carrying ability of the lubricant. Reported as "A" Acceptable (0-3%), "C" Caution (3-5%),"E" Excessive(Over 5%).

SOOT: By-Product of combustion. Causes increased viscosity (thickening). Can trap abrasive contaminants and wear metals in the matrix increasing wear.

AN: (Formerly TAN) Acid Number. Measures acidic material in lubricants. Usually (but not always) indicates potential for corrosive wear.

BN: (Formerly TBN) Base Number. Measures the alkaline reserve of the lubricant (ability to neutralize acid).Usually for diesel engine lubricants.

FT-IR (Fourier Transform Infra-red) ANALYSIS: Detects water, soot, oxidation, antifreeze, fuel dilution and nitration.. Also useful as a QA/QC check.

PARTICLE COUNT: Particle counters report particulate levels in a fluid. Results are given in the number of particles per ml. in six size ranges. ISO cleanliness levels is also given. Mostly used in hydraulic and gear oil samples to determine how clean the oil is.

ATTENTION CODES: An attention code beneath any results of "L" indicates slightly low. "B" is abnormally low, "C" is critically low and "D" is extremely low. See "Attention codes" on the report for other attention codes. Remarks and comments are advisory only and are based on the assumption that the sample is representative and data submitted is valid. Missing information limits the evaluation. No Warranty is expressed or implied.