Where a coolant’s neutralization number is related to the quantity of acid- or base-forming materials in a solution, pH indicates their intensity – and can indicate things going wrong in the cooling system.
Oil and coolant are like your blood and your sweat, respectively, and they have to work together to keep you alive, explains Dave Tingey, senior data analyst with Polaris Laboratories.
“If your body is sweating while you’re running, you’re healthy,” he explains. “If you stop sweating, your blood is going to heat up, and you’re going to die. If your coolant doesn’t do its job, it’s going to oxidize that oil prematurely, and next thing you know, your vehicle’s going to die.”
Like your body, your engine fluids should have regular tests to check on their health. Here are 12 things you should know about today’s oil and coolant analysis.
1. It’s not your granddaddy’s engine.
New engines, new fuels and new coolants have affected various aspects of fluid analysis.
“With the constant reformulation of your coolants and your oils, the constant upgrading and redesign of your engines to meet emissions specifications, the loads put on oil have to be understood, and you have to realize how to best manage that piece of equipment,” Tingey says. “Oil and coolant analysis give you the ability to do that.”
Elizabeth Nelson, coolant program manager at Polaris Laboratories, also notes that today’s cooling systems have higher temperatures, higher coolant flow rates and higher pressures. “There’s a lot more going on than back in the ’70s because of the evolution of that engine.”
One area of significant concern is coolant leaks in oil over the past few years. With exhaust gas recirculation coolers a feature on new trucks since 2007, labs and fleets also have reported a frustratingly high number of EGR cooler leaks.
In fact, according to Mark Betner, heavy-duty lubricants manager with Citgo, 50% of premature lube-related engine failures in on-highway trucks are related to coolant contamination.
Oil analysis can help catch coolant contamination in the oil before you see significant engine damage, and coolant analysis can help detect something wrong with the cooling system.
2. There have been advancements in testing.
For instance, the advent of ultra-low-sulfur diesel has required a change in the way labs look for fuel dilution in the oil. In the past, tests would look for trace elements of sulfur. Without as much sulfur, explains Tingey, Polaris Laboratories has switched to gas chromatography to measure the amount of raw fuel in the oil.
ULSD also has affected the importance of measuring TBN – total base number, a measure of the acid-neutralizing capacity of oil.
“Back when we had higher levels of sulfur in the fuel, the engine would generate sulfuric acid, so you needed to follow TBN very closely,” says Stede Granger, OEM technical services manager with Shell Lubricants. “With the use of ULSD, we don’t generate sulfuric acid in the crankcase anymore. There are other acids that form, but they are not as hard. So the focus on TBN just doesn’t have to be what it was before.”
Another advancement in testing, says Peter Thompson, director of marketing for Valvoline, is microscopic particle examination. “It really gives detailed information on different wear particles,” he explains. Traditional wear metal testing gives you a quantity, say 50 ppm of iron, he says, “but it can’t tell you the makeup of that metal and likely where it came from – a liner or camshaft, for instance.”
Chuck Hamilton with CHS notes that ferrous metal (iron) content testing has become available at many used oil analysis labs, using a Particle Quantification Index (PQI). This test will pick up the presence of larger iron particles, such as a gear tooth or slivers, which would not be picked up by the more typical spectroscopic iron measurement, which detects particles 8 microns or smaller.
3. Oil analysis can prevent premature wear and catastrophic failure.
With oil analysis, “You can see problems that are coming down the line with the engine,” says Henry Neicamp, field services manager for Polaris Laboratories. “So you can correct that situation instead of waiting till the engine has a failure. It doesn’t cost that much to do oil sample analysis, but the cost avoidance is significant as opposed to a significant engine repair and its resultant loss of productivity and downtime.”
Steph Sabo, maintenance manager for Norrenberns Truck Service, a fleet and repair operation in Nashville, Ill., says while oil analysis has never prevented a catastrophic failure for his fleet, it has found a good many head gasket leaks and dust getting into the engine from bad air cleaner tubing connections.
Shell’s Granger says with oil analysis, “you can actually see if you’re starting to inhale dirt into the combustion chamber, because you see that in the crankcase in elevated silicates. Years ago I saw an engine where that had happened; it’s amazing the amount of engine wear that took place.”
Because oil analysis can alert you to situations where the oil’s no longer protecting the engine as it should, it’s a must if you want to extend your oil drain intervals beyond the standard recommended by your engine maker.
Some of the telltale signs of problems oil analysis looks for in determining drain intervals is viscosity (oil thickening due to soot accumulation and oil oxidation), the ability of the oil to neutralize acid (although that’s not as critical as it once was), as well as contaminants such as coolant, fuel, water, debris or wear metals.
4. Coolant analysis is more than checking additive levels.
It’s not just oil analysis that can help catch damaging problems early. Traditionally, coolant testing in the field has focused on additive levels and whether there’s the right concentration of coolant vs. water. But coolant testing can do much more.
“People tend to put [coolant] in and forget it, but there are mechanical things that take place in the cooling system that will destroy that coolant, and the coolant in turn will attack the metals in the engine,” Nelson says.
Laboratory testing can catch cooling system problems early, such as combustion gas leaks, electrical ground problems, localized overheating issues and air leaks.
For instance, Nelson says, pH levels can not only tell you if someone mixed a conventional fluid with an extended-life organic additive coolant, but also whether there is a chemical reaction taking place in the cooling system.
“When pH starts to drop significantly, that’s a clue there’s something wrong, such as the formation of degradation acids or an air leak,” she says. Glycol, the foundation ingredient of coolants, can break down in excessive heat, forming degradation acids, and that can cause severe pitting in the cooling system. “And that can come from something simple like a defective pressure cap, or corrosion and dirt plugging up cooling system passages.”
Polaris Laboratories recommends twice a year, before summer and before winter.
5. More coolants mean more potential for mix-ups.
Increasingly popular extended-life coolants are based on organic additive technology, which doesn’t work the same as traditional coolants. Sometimes even different brands of extended-life technology don’t play well together.
As Shell’s Granger explains, “We do not recommend mixing, because your corrosion protection could significantly suffer. The additives in the [traditional] silicate product protect against corrosion in a much different manner than an extended-life coolant. When you mix the two, you may end up without enough of either type of additive to protect against corrosion.”
Making it more difficult is that you don’t see much in the way of the easy dip-a-strip type of tests for ELC that worked on the traditional coolants.
There are some test kits out there. Shell, for instance, just introduced a new coolant contamination test tool for its Rotella extended-life coolants and other leading brands, which uses two vials and three simple color indications. Its purpose is to make sure traditional coolant has not been mixed in with the ELC.
But don’t automatically assume that a test that works for one brand of extended life coolant will work for another. “There are about 16 different organic additives that can be used, and at different levels,” says Polaris Laboratories’ Nelson.
In addition, there’s a new “waterless” coolant on the scene. Evans coolant, because it’s made with glycols undiluted by water, boils at a higher temperature than regular coolant, allowing for reduced fan-on time and fuel savings, according to the company. This also means a very different additive package – without water, non-corrosive additives aren’t required, for instance. So for this coolant, the biggest thing to test for is the accidental addition of water.
6. Test results are easier to understand than before.
Once upon a time, you mailed off an oil or coolant sample and it took weeks to get the results back in the mail – and then all too often it was a confusing mishmash that it seemed you needed to be both a mathematician and chemist to understand.
Today, however, the information is transmitted electronically.
“Instead of reading the old paper reports, more and more companies are utilizing software and better electronic delivery methods from used oil labs to receive quicker data and help them better manage their maintenance programs,” explains Len Badal, commercial sector manager, Chevron Lubricants.
With most programs, you can pull up the results via a website and analyze individual vehicles, slice and dice by make of engine or other parameters. E-mail reports can alert you to abnormal and critical results.
Good labs also will have people available to answer questions about your results. “We don’t expect fleet operators to be experts on analysis,” says Valvoline’s Thomson. “Our technical people also get involved to help interpret the results.”
7. Alternative fuels can change things.
If you’re running alternative fuels, fluid analysis may be even more important – and you’ll need to check with your lab or supplier about special tests to run.
When using a biodiesel blend in your engines, you need to keep an extra-close eye on fuel dilution in your oil. Biodiesel doesn’t evaporate the way regular diesel does, so if some gets into your oil, it’s more likely to stay there.
Natural-gas engines may run hotter than comparable diesels, and compressed natural gas may cause nitration in the oil. Nitration can thicken the oil and cause premature dropout of varnish and sludge.
Those higher temps with CNG also can make a difference on the cooling side, Nelson says. “The chemical reactions [in the cooling system] are dependent on temperatures, pressures and flows. So I do see issues at times because temps are a little higher.”
8. Be careful when switching analysis providers.
Different laboratories may test for different contaminants and chemicals in different ways. So if you switch oil analysis providers, the results may not be comparable.
Tingey explains that you can see if the old lab and the new lab are using the same testing method by looking at what ASTM method they’re following. For instance, he says, some labs may test for fuel dilution using FTIR, which has a certain ASTM method associated with it, while Polaris Laboratories uses gas chromatography, which is a different ASTM method.
Another thing to look for when choosing a lab is whether they are ISO 17025:2005 accredited. This is an international standard for calibration and testing laboratories. Unlike an ISO 9000 certification, which is primarily a documentation standard, this standard has to do with consistency of testing and data.
9. It won’t do any good if you don’t do it right.
“The biggest bugaboo about oil analysis is they don’t do it right,” says Citgo’s Betner. People don’t take samples regularly, they are sloppy and get contamination in the sample, they don’t label it right, they don’t know how to read the report, they don’t understand the data.
Betner puts it this way: “If you go to the doctor and get a blood pressure check, how does he tell you to check your blood pressure? Does he tell you to go to Walmart and stick your arm in a cuff once a year? No, the doctor will tell you to do it once in the morning, once in the evening, for three or four days to establish a trend.”
Similarly, you need to establish a trend, a fingerprint, for each particular engine. That way, when you get a marked departure in wear rates or oil condition trends, you’ll have something to compare the data to.
Keep in mind that results can vary by engine manufacturer, engine type, oil capacity, whether there’s a bypass oil filtration system, etc.
Fleets often have the misconception that “if samples come back normal, it is not necessary to take additional samples at regular intervals,” says CHS’ Hamilton. “The same is true for the coolant analysis, if it is normal they feel the coolant is good for the life of the unit.”
Valvoline’s Thompson says the first thing a fleet should do is work with their oil supplier or lab to figure out what the sample schedule should be, which will vary based on the compartments you’re sampling (engine oil, coolant, axles.) You need to identify the sample points you’re going to use, and use the same sample point each time.
Take care when taking samples to avoid contamination – don’t just grab any jar that happens to be lying around! – and make sure the machine is at normal operating temperature.
“One of the biggest issues we see is poor labeling of the samples – the wrong mileage, the wrong truck number – and people missing their scheduled sampling,” Thomson says. “Things can go from green to red really quickly.”
10. You can’t just file away the reports.
The key to making fluid analysis worthwhile, Sabo says, is one, really understanding what you get from the oil analysis company, and two, taking action on those results. “No one wants to spend money unnecessarily,” he says, “and taking action means spending money.”
Polaris Laboratories’ Neicamp says too many maintenance managers just print out fluid analysis reports and put them in a filing cabinet. “They don’t see the value in it; they’re just doing it because they were told to do it.” Fluid analysis on its own can’t accomplish anything unless you do something with it.
That’s why you need to work with a lab that will help you understand your results.
“The key value derives from establishing what the fleet wants to measure, along with establishing it as part of their maintenance program,” says Chevron’s Badal.
As Citgo’s Betner says, it doesn’t matter how good the lab is; “If the program is not implemented properly, it’s like having a high-tech performance car and not knowing how to drive.”
11. There are more ways fluid analysis can help.
There are some other benefits oil and coolant analysis can offer:
– Increase resale value by being able to provide complete fluid analysis history.
– Prove to yourself the value of premium-quality oils.
– Use it as a tool to measure maintenance quality at different shop locations.
– Use it as a tool to compare equipment to help in future purchase decisions.
12. Fluid analysis is not a cure-all.
All too often, truck owners give up on oil analysis because it didn’t show anything wrong, and the engine failed the next day. Oil analysis is just one tool; it can’t show you everything that can go wrong in your engine. The same, of course, goes for coolant analysis.
Nevertheless, it’s important. “We have done a lot of different stuff with engine oil,” says Sabo, from testing different oils to running bypass oil filtration. “The one thing I have really learned is that engine oil is like a person’s blood. You better keep it clean, or the body shuts down. We have shut down some engines from ‘bad blood’ … and that’s real expensive.”
New TMC RP for coolant analysis
The Technology and Maintenance Council of the American Trucking Associations now has a Recommended Practice on used coolant analysis for heavy-duty vehicles, RP-362.
The RP provides guidelines for cooling system sampling procedures, commonly run field and laboratory tests, and warning/condemnation limits for used engine coolants.
These sampling procedures and tests are especially critical in monitoring corrosion inhibitors that deplete at different rates under high engine load factors and higher operating temperatures, noted TMC’s Marsh Galloway in a recent TMC Fleet Advisor newsletter.
RP 362 provides guidelines for testing intervals, guidelines for sampling procedures for both on-site field testing and testing in the laboratory, easy-to-understand charts and a glossary of terms.
From the October 2011 issue of HDT.
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