Robust oil analysis for optimum equipment performance
If a doctor suspects a patient has a liver problem, it is most unlikely that he will cut him open and take a look. Instead, the patient will be sent for a blood test, and the blood will be analysed for traces of substances that might indicate a decline in liver function. The test results will inform decisions about further treatment.
Lubricant analysis enables similar action to be taken with engines and transmissions. Analysis of a small sample of used oil drawn from the unit can answer questions about its maintenance and mechanical health, and the condition of the oil itself, without dismantling. A competent analysis, as found with Texaco’s Lubewatch programme, will examine two main areas. One is the oil’s condition and the other is the presence of contaminants. Skilled interpretation can identify potential problems with a unit before a physical breakdown.
Looking at the oil’s condition, a change in viscosity can indicate excessive contamination with an alien fluid or colloidal particles, or that the oil itself has become thickened through overheating. An infrared spectrometer can also identify heat-related lubricant oxidation or nitration, both of which impair the protective qualities of the lubricant, and can also lead to acidification, which can be confirmed by a separate test.
These results may point to the unit being either overworked or undercooled; or they may merely indicate that the lubricant is due for change. Besides the inevitable changes to the lubricant itself in use, lubricant analysis will also pick up various contaminants in circulation. Some will be the result of normal wear and tear, while others indicate failures.
For instance, a certain amount of soot contamination is inevitable in engine lubricants and is largely determined by the running hours since the oil was changed. But a sudden spike indicates contamination with unburned fuel, suggesting an injector leakage problem. The presence of glycol and/or water shows the lubricant is being contaminated by engine coolant, and there is a likely seal or gasket leakage.
High silica content can mean that airborne dust is entering the engine, and there is a filtration issue. If left untreated, this will result in increased top-end engine wear. Increased traces of various metals (so-called wear metals) indicate that bearings, rings and other friction components are wearing out.
So, regular analysis with programmes such as Texaco Lubewatch will help operators time oil changes to get the most out of their lubricants and flag-up potential problems before they become disasters.
