Stop work and switch off the engine whenever you see these crimson flags on an oil evaluation report

Oil evaluation can present you tendencies within the well being of your engines and oil. It might additionally tip you off to eminent catastrophic failure.

When you catch these issues early sufficient, you possibly can repair the underlying downside, drain and refill the crankcase with new oil, and monitor the outcomes with additional oil evaluation, saving hundreds of dollars in emergency repairs and presumably stop a ruined engine.


Extreme contamination

“A considerable amount of coolant – ethylene glycol – within the engine oil could be fairly excessive on my record,” says Stede Granger, OEM technical service supervisor for Shell Lubricants. Which means a leak someplace between the elements of the engine containing lube oil and the elements of the engine carrying coolant.

As we speak’s engines have a number of cooling programs – the principle radiator for engine cooling, but additionally oil coolers and EGR coolers as nicely. A leak in certainly one of these from a gasket or becoming requires a direct repair. If not, the sluggish drip of coolant into the lube oil may contaminate the oil, leading to overheating, corrosion or injury to the engine.

Most labs verify for water, however water by itself shouldn’t be a assured indicator of coolant leaks, says Granger. “Because the engine heats up the water and even ethylene glycol will evaporate. However we typically see telltale indicators of coolant components, usually potassium or sodium, relying on the kind of coolant they’re utilizing.”

Two to 4 hundred elements per million of potassium or sodium is the higher restrict, says Granger. As for water, something above 500 ppm is trigger for quick corrective motion, he says.


Gas within the oil

Gas dilution of lube oil is one other large trigger for concern and might trigger engine injury. It has the identical impact as water or coolant dilution besides gasoline doesn’t burn off as simply. Gas can get into your lube oil by way of worn or broken piston rings, leaky injectors, misfires, dangerous timing or the emissions system.

“I’ve seen some actually excessive gasoline dilution ranges, as much as 10 p.c, within the engine oil, so that will be one to control,” says Granger. Gas dilution can decrease your viscosity, lowering high-temperature efficiency which might mitigate the protecting qualities of your lube oil, leading to accelerated put on on the engine.

Trendy engines are getting higher. Exhaust blow-by has been diminished, gasoline injection is extra exactly managed, and ring packs have been improved. However not like water, which burns off because the engine heats up, gasoline dilution is accumulative. “It’s not as large an issue because it was once, nevertheless it’s nonetheless one thing to look out for,” says Granger.



Not all vandalism reveals up as spray paint and smashed glass. Vandals and disgruntled staff have been identified to place water, molasses, even DEF fluid within the gasoline tank of an idle truck or piece of kit. And when any overseas substances get into the gasoline, they’ll overwhelm the lube oil’s means to guard the engine, Granger says.

Oil evaluation can detect this contamination, however given the time between oil modifications right this moment (as a lot as 500 hours of engine time), you might not catch it instantly. When you’re having engine failures you possibly can’t diagnose, get a fast oil pattern and search for any anomalies or spikes within the development traces. Extreme water or a loopy viscosity quantity might point out vandalism, says Granger.



Silicon is one other contaminant to maintain your eye on. It usually comes from one or two sources. One supply is coolant components. Outdated-style coolants had silicon in them, however new extended-life formulations don’t. Nonetheless, says Granger, some individuals choose to maintain utilizing the silicate formulation.

The opposite supply is a leak in your air filtration system. Silica is current within the mud usually kicked up on jobsites. As we speak’s air filtration programs do an amazing job of eliminating this contaminant out of your engine’s air stream, Granger says. However a gap in your filter media or a leak in your system may cause a sudden spike in silica ranges.

“After I see silica ranges above 10 ppm, then it will get a little bit regarding,” says Granger. “At 400 to 500 ppm, these silica particles may actually be sandblasting the within of your engine.”


Incorrect oil

The present API CK-4 licensed lube oils will work in most heavy diesel engines, however there’s a chance anyone may fill with the incorrect product throughout an oil change. On this case, the oil evaluation will present components like zinc and phosphorus current in quantities clearly not indicative of OEM-recommended engine oil, says David Fields, supervisor Cummins OilGuard. This may increasingly trigger a wide range of issues, even main engine put on or failure, relying on the fluid used, says Fields.


Skipped oil change

Overly degraded oil brought on by extreme obligation cycle or going past really useful oil drain intervals can result in excessive oil oxidation and viscosity, says Fields. This may additionally occur when anyone skips or forgets a scheduled oil change. Degraded oil may cause lead or copper corrosion in bearings and bushings, which is able to present up as a spike within the put on metals on the subsequent oil pattern. The thickened oil also can hurt the lubrication system.


Essential however not at all times vital

Along with varied types of contamination, you need to verify  viscosity, whole base quantity/whole acid quantity (TBN/TAN), soot ranges  and oxidation. One studying received’t let you know a lot, however by doing an oil evaluation with each oil change, you possibly can see tendencies in these parameters over time that may assist you to fine-tune your upkeep program.

A profitable oil evaluation program requires good practices and recordkeeping and a bit of information about what the outcomes imply. But it surely’s nothing you possibly can’t study from supplier. Select a lab that can crimson flag any vital points and work with you to develop your information of this important measure of your fleet’s well being.