ACTON, Ont. - It doesn't take a chemical engineer to pull a dipstick and determine if the oil needs changing. And with today's computer generated preventative maintenance schedules (PMs), it has actua...
TROUBLESHOOTING: Oil analysis can help direct you to proper maintenance. (ExxonMobil photo)
ACTON, Ont. – It doesn’t take a chemical engineer to pull a dipstick and determine if the oil needs changing. And with today’s computer generated preventative maintenance schedules (PMs), it has actually got to the point where you don’t have to pull out the dipstick at all.
It does take a chemical engineer, however, to tell you if there is more in your oil that just dirt, and that is where someone like Wayne Burtney comes in. Burtney is, in fact, a chemical engineer, and he is also the president of Acton, Ont.-based Diagnostic Oil Analysis Inc., a company that specializes in analyzing oil samples taken from everything from diesel truck motors to hydraulic parts. For around $16 a sample, Burtney can tell you exactly what elements are in your oil and in what quantities, plus tell you how they most likely got there.
“Most people come to me either when they have had a problem and they are trying to find out what caused it, or they suspect they have a problem and they want to make sure,” Burtney said. “The majority of truck oil samples are done to confirm a fuel leak or a coolant leak.”
Some fleets use oil analysis to help direct maintenance troubleshooting when they suspect a problem. If a coolant leak is suspected, explains Burtney, oil analysis might be able to tell where the leak is located. A high level of coolant in the oil might suggest a leak lower in the engine, while burnt coolant, which shows up as high levels of sodium, might mean a head problem.
Of course, all oil analysis starts with knowing what is supposed to be there in the first place. That begins with the basic refined substance that makes up engine oil, known as paraffinic base stock. After that come the additives, a variety of compounds mixed with the base product to perform certain functions in the oil or to help the oil do its job. These include things such as anti-oxidants, anti-wear agents, corrosion inhibitors, viscosity index improvers, foam suppressants and detergents, and they can account for as much as 20 per cent of the make-up of the oil.
“People are surprised when I tell them there are detergents in oil, but it is true,” laughs Burtney. “And they are virtually the same as the detergents used for doing laundry.”
Detergents in oil keep various molecules from clumping together and forming deposits in the engine. They also work to remove deposits that have already established themselves, say, like a coffee stain on a white shirt. One such detergent commonly used in engine oil is the element boron, which is also a major ingredient in Borax laundry soap.
Once all the normal components of the engine oil are accounted for, analysis of the sample can turn to identifying elements that either should not be present or are present in a concentration that’s too high. “I look for wear metals, contaminants, traces of fuel or coolant, and I test the oil for viscosity breakdown,” Burtney said.
Wear metals are actually microscopic fragments of metal from various engine components, measured in parts per million. These fragments break or sheer off under the tremendous forces of friction and pressure that are constantly at work inside the motor as it operates. It is normal for wear metals to be present in engine oil at certain levels, but when these levels are exceeded, it could be evidence of chronic or severe wear. By knowing the type of metals used in the various parts of a particular engine, Burtney is able to estimate which components are wearing the fastest.
The wear metals that need to be measured through an oil analysis depend on the type of engine the oil came out of, because every manufacturer is different, Burtney said. For example, some engines have pistons made of a tin/aluminum alloy while others have steel pistons plated with tin. Still other engines use solid aluminum pistons. Iron can come from the cylinder walls, and rings are a source of both iron and chromium. Bearings are another common source of aluminum, but there are some engine makes that utilize lead/copper bearings. “It gets really tricky when you get into the aftermarket parts,” Burtney said.
“An owner/operator was experiencing power loss that he couldn’t account for, so we did an analysis and found there was a lot of aluminum showing up,” Burtney recalls. “Given the type of truck he was driving, we knew right away it was likely the bearings in the turbo wearing. He had it checked, and sure enough, he was getting impeller wear on the inside of the housing”
Particles in the oil are measured in microns, which are 39 millionths of an inch, or .000039 inches, in size. Just for a point of reference, a grain of salt is about 60 microns across, and the human eye can see things as small as about 40 microns. Wear on engine parts shows up as “fatigue platelets” in the oil. These are usually 20 to 40 microns is size, but an unusually high amount of platelets or an increase in their size could indicate excessive wear.
Aside from wear metals, oil analysis can also identify the presence of a variety of contaminants from both inside and outside the engine. These include things like fuel, water, sludge, varnish, lacquer, carbon and dust. Fuel contamination is generally caused by blow-by, or the forcing of unburned fuel past the piston rings, while water usually comes from condensation. Sludge, varnish, and lacquer are formed when chemicals like oil additives react with the metal under extreme heat. Carbon, meanwhile, is left behind when oil is subjected to extreme heat, like on the end of a spark plug. The presence of dust and dirt usually means there is a filtration problem
“If the motor has a cracked air intake, we can tell how long the system has been open to the atmosphere and how much wear has taken place in the engine,” explains Burtney. In fact, it is sometimes possible to tell when a problem started. “If a vehicle was running in Quebec, the oil will have traces of aluminum and titanium in it, because that is what is in the soil there. In Ontario, we would look for more iron oxide.”
Oil analysis can’t fix a problem that has already occurred, but it can give a heads-up on a potential problem down the road. Burtney said most fleets and owner/operators simply don’t feel the process is cost-effective or simply can’t be bothered. Those fleets that do are usually ones that depend on preventative maintenance because they absolutely can not afford to have a vehicle go down with a catastrophic failure
“A good example is a garbage truck with a municipal contract. If the truck breaks down, there are going to be a lot of angry people calling city hall,” he said.
Burtney cautions, however, that he can only tell the operator what has happened with a given engine since the last time the oil was changed. “An engine could be totally worn out, but it won’t show up after you change the oil.” n
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