Machinery Lubrication

Machinery Lubrication September October

Machinery Lubrication magazine published by Noria Corporation

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42 | September - October 2016 | www.machinerylubrication.com the dipstick port via the drop-tube method or from the drain port during an oil change. These are only a few of the reasons why there isn't much of a market for oil analysis of passenger vehicles. However, one of the most important aspects of oil analysis is often over - looked, which is the ability to provide information about the contamination and wear debris in the oil. Why Passenger Vehicle Oil Analysis Should Be Performed Oil analysis not only is effective in offering indicators of oil condition, but it can also iden- tify various forms of contamination and wear debris as an engine condition monitoring indi- cator. This should be of even greater importance, since the longevity of the engine and the vehicle is the goal of any analysis performed, not just the quality and longevity of the oil. The bulk of oil analysis performed in North America is on diesel engine oil. This is because the vast majority of these diesel engines are powering heavy-duty trucks for large transpor - tation fleets or industries with off-road equipment. These fleet owners and owner-oper- ators are reliant on the continuous operation of their trucks to produce revenue and income. This dependence can be risky, and thus oil anal- ysis provides them with an added level of assurance toward improved reliability. Oil analysis can be just as beneficial to most owners and drivers of passenger vehicles if the right information is obtained. Among the key questions to ask about the oil in your car include: • Is the right oil being used? • Are certain additives or base oil proper- ties depleting or degrading too rapidly? • Are there external contaminants in my oil that shouldn't be there? • Are there internal contaminants like fuel, soot, coolant, etc.? • Is there an indication that the engine is generating abnormal amounts of wear? • Is the type of wear indicative of an incip- ient failure? • Is the cause of the generated wear unique to a known type of failure? Where and How Often to Perform Oil Analysis With most oil analysis of industrial plant equipment, a sample is collected every "X" number of weeks or months and evaluated using a predetermined set of routine tests. This is practical when the cost of oil extraction and replenishment is reason enough to extend the drain interval until it has reached its condemning limit and when pulling a sample during operation is effortless because of an installed sample port. Even if it isn't costly to replenish the oil, it may be important to monitor machine conditions through oil anal - ysis simply because the machine is critical. The typical passenger vehicle is not equipped for proper oil sampling during oper- ation. The ideal sampling location would be on the pressure line between the pump and filter on a wet-sump system. Since this is not feasible, it generally is better to opt for sampling at the drain port during a drain-and- fill or via the drop-tube vacuum sampling method. Keep in mind that there are best-practice procedures for these two sampling locations that should be considered before continuing with these approaches. Sampling frequency is primarily based on the potential for oil analysis to offer an early indication of an unusual contamination issue, rapidly degrading oil or impending machine failure condition. Oil analysis is unique in that it can detect a possible concern long before other sensors or external symptoms are often triggered. Since oil drains normally are more frequent in passenger vehicles than other machinery, the best sampling interval for the engine most likely would be right before the scheduled drain interval. As long as the sampling interval time is normalized relative to the previous oil change, the individual interpreting the data has an opportunity to effectively trend the data points. This strategy is beneficial because it not only will yield a variety of information about the engine's health but also help determine if the current drain interval is too long or short. Which Tests to Use Engine oils can be analyzed to obtain valu- able information about their properties, contaminants or wear debris. The instruments in an oil analysis laboratory may focus on one specific piece of information or be designed to report multiple points of information. The following are some of the most common oil analysis tests for used engine oils. Viscosity This test measures a fluid's resistance to flow and shear. Viscosity is an oil's most important property. It provides the basic function for creating a film thickness between mechanical surfaces moving relative to one another. The engine oil in your vehicle is formulated to match a particular viscosity. If the viscosity changes, the oil may not be suffi - cient to protect the engine's surfaces. It can also mean that the oil has chemically degraded or been affected by a contaminant such as water, fuel or glycol. When this occurs, it will be necessary to further investigate the poten - tial root causes with other oil analysis tests. Base Number Base number testing is used to measure the reserve alkalinity within the oil. This character- istic of engine oils is intended to neutralize the acidic compounds to which the oil may be exposed through blow-by contaminants. The base number will trend downward as the oil ages, but a rapid change could be an indicator of increased blow-by contaminants due to inef - ficiencies in the combustion zone, severe running conditions or using the wrong oil. Particle Count A particle count test identifies the level of general contamination in the form of three numbers representing the amount of contam- inants greater than 4, 6 and 14 microns per milliliter of fluid. Contamination exposure to the engine oil can be detrimental, but it is expected during operation of the vehicle. Particle counting results can tell you several things, such as the potential ineffectiveness of LESSONS IN LUBRICATION 75% of lubrication professionals do not perform oil analysis on their car's engine oil, based on a recent survey at MachineryLubrication.com

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