Used oil analysis provides a critical look at your engine’s true condition

Words: Cindy Bullion

“Knowledge is power.” The phrase first used in the late 1500s has grown to widespread use today, the reason being that it’s true. Having facts allows you to make wise decisions. When it comes to protecting your performance engine, a used oil analysis gives you those facts necessary to select the right oil and establish a proper maintenance schedule.

“Everybody has opinions about motor oils, but you can make decisions based on facts instead of speculation and opinion,” says Lake Speed Jr., Certified Lubrication Specialist for Driven Racing Oil. Speed says a used oil analysis will help you navigate the challenges of your application, be it a diesel truck, street rod, naturally aspirated drag car, boat, or motorcycle. Each one comes with different oil requirements, and demands.

We asked Speed to explain the basics behind interpreting a used oil analysis report, which includes information such as viscosity and the concentration of dirt, wear metals, and water present in the oil. But, we first must tackle sample-taking and getting the oil to the lab.

“Doing a used oil analysis may sound complicated, but it’s ridiculously easy and not very expensive,” says Speed.

You can typically find a used oil analysis kit for less than $30 at a heavy equipment dealership, like John Deere or Caterpillar.

Once in hand, you use the kit’s sample cup to collect three ounces of oil directly from the engine within a few minutes of turning it off. Performing the collection when the engine is still warm ensures the oil has been well circulated and the sample will be representative. The next step is filling out the enclosed form and mailing the sample to the lab. Feel free to go the regular mail route, as the small amount of oil is not considered hazardous.

A used oil analysis kit can typically be found at a heavy equipment dealership and includes a sample container — fill it with 3 ounces of oil — collection form, and return envelope, all which can be sent to the lab by regular mail.

According to Speed, you should have results back from the lab within a few days. He adds that while the lab report will provide a general interpretation — no Ph.D needed — there may not always be a specific problem pinpointed. The provided details are valuable when troubleshooting, however.

“While correctly interpreting oil analysis results is critical for making good decisions about preventive maintenance,” says Speed, “it is a skill that is easily learned with a little bit of experience and some training.”

He offers the following tips to help you with deeper interpretation and determining what, if any, changes are necessary.

Every report should be checked to make sure it includes your provided information, such as sample date, mileage on the oil, type of oil, and engine type. Next, look for the lab’s explanation of its rating system; most will have ranges for normal, marginal, and critical levels. The report will rate the oil and engine in multiple test areas, and may also include analyst comments you can use to gauge the severity of problems and determine a course of action.

Viscosity
Viscosity is an oil’s most important property and, thus, the first item to review on a used oil analysis report. In the lab, an analyst tests the oil’s resistance to flow at a specific temperature, since if the oil cannot get where it is needed in the engine, fast enough, it cannot protect components. An incorrect viscosity also means the oil cannot establish the necessary protective film nor carry away heat and contamination at the appropriate rate, even if it does timely flow through the engine.

Speed says the effects of incorrect viscosity could include overheating, accelerated wear, and eventual engine failure. So, identifying a viscosity issue through used oil analysis could save a lot of headache — and money — down the road.

On your used oil analysis report, a 20 percent or greater change in viscosity from the new oil to sample represents a critical viscosity issue that needs immediate attention. A marginal change would be greater than 10 percent, and still warrants a change.

Wear materials
With any oil, there is a certain amount of elements, like zinc and phosphorous, you should expect to see show up on a used oil analysis report. That’s why Speed recommends having a new oil sample analyzed as well, to determine a baseline reference. You can then deduct those amounts from the used oil analysis report to see what else your oil picked up.

This sample used oil analysis report is representative of what you may receive back from the lab. Look for line items that are marked as being at marginal and critical levels, as well as any analyst comments. This data can be useful in determining whether to select a different oil, change your maintenance schedule, or if you have an internal engine problem that needs addressed.

Contaminants can make their way into oil as it circulates through the engine, during engine repairs, or from poor filters or breathers. Regardless, they can lead to damage in the engine that shows up in your oil as wear metals, such as iron or aluminum.

The elemental section of your used oil analysis report will show the concentration of wear metals, contaminant metals, and additive metals. A change greater than 100 ppm is cause for alarm, with greater than 50 ppm change begging caution. Any change less than 20 ppm is usually nothing to worry about. Speed notes elemental analysis cannot measure metal particles larger than 10 microns, but if particles that large are in your oil, there are likely plenty of smaller ones the analysis will detect.

When reviewing wear metal concentration in your oil, Speed says it’s important to take into account engine history and look for trends. The best way to gauge if something in the engine is truly amiss is to review previous used oil analysis reports — get these every 6 months to a year for a road car and after a few runs for a race car. If your most recent report is greatly different from the last, consider whether operating conditions have changed, the engine has been running longer or under more load, etc.

Even the smallest dust, sand, and rubber particles can affect oil performance and damage your oil system, much less an engine, as earlier noted. A used oil analysis will tell you what contaminants are present so you can start looking for their point of entry and close it.

Contaminants are usually reflected on a used oil analysis report as silicon, boron, potassium, or sodium. Water may also show up on a report, though its effects on oil and your engine greatly differ.

Where particle contaminants directly cause wear on engine surfaces, water promotes rust and corrosion and hampers the oil’s protective ability. It reduces the oil’s load-carrying ability and depletes additives, creating higher operating temperatures and in-creased friction that leads to accelerated wear. Unchecked, water can cause premature engine failure.

Speed says the Karl Fischer water test is the most common used for analyzing water in oil, with a result of more than 500 ppm being abnormal. Lower levels of water are typically due to condensation, rather than external contamination or internal leaks, both which should be identified and corrected.

In the end, knowing what’s in your oil or how it has changed through use will give you the power to keep, or get, your engine operating at best. Even if it shows you need a different oil or to make system adjustments or corrections, that occasional $30 for a used oil analysis will have been well spent. Wouldn’t you rather change something small than replace a whole engine?

Source

Driven Racing Oil
drivenracingoil.com