Critical Information

Evan Zabawski | TLT From the Editor February 2011

‘This is important. This means something.’

Just because we don’t have an obvious clue doesn’t mean we can’t arrive at the likeliest answer. We just have to look harder.

Interpreting used oil analysis reports correctly and efficiently involves assessing the data, determining identifying trends or correlations and selecting the most appropriate action. When I am training others to help them improve these skills, I often find the final step is the most difficult to learn.

For example, it doesn’t seem to be difficult to identify that iron, calcium and magnesium, all at elevated levels in a sample, may be either hard water ingression causing rust or Fuller’s Earth (aka kitty litter or floor sweep) contamination due to airborne ingression. The difficult question is that if both are possible, how can you deduce the correct one from the report? Detectable water or elevated particle counts would easily isolate either possibility, but if neither show any change or were not measured, where do you look? You have to find that piece of critical information that is not necessarily obvious but equally as definitive.

This concept occurred to me on a recent flight where the video-on-demand let me view one of my all-time favorite sci-fi films, and I was mentally tabulating some similarities it holds with another film. Let me create a demonstrative exercise whereby you, the reader who is hopefully a minor film buff and sci-fi fan, have to deduce the title.

The film, released in 1977, was the third major release for the director, and John Williams composed the iconic score. The director had previously worked with the main actor, who rose to stardom after appearing in American Graffiti. The director would later join forces with another famous director when he directed Raiders of the Lost Ark. The film was re-released years later with additional footage and enhanced special effects.

Now most of you are probably thinking the film is Star Wars, but the answer is actually Close Encounters of the Third Kind. Both films are similar in each regard, but the one critical piece of information is knowing who directed Raiders of the Lost Ark. George Lucas, director of Star Wars, acted as executive producer and writer, while Steven Spielberg directed. You might have known both directors were involved, but knowing which one actually directed was critical for proper deduction.

Our minds automatically go to the more commonly known or higher profile answer; we can’t help it. Our experience plays a significant role as many have viewed Star Wars (even multiple times), but far fewer have watched Close Encounters. If you were a fan or had seen Close Encounters recently, you might have picked up on the clue in the subtitle of this article—it quotes one of the most popular lines from the film.

We need to read all the facts without making assumptions and jumping to conclusions. When we don’t know we cannot simply guess; we must keep looking or ask more questions.

Returning to the oil analysis example, which piece of information is critical? The critical piece of information in this case could be another wear metal like copper or lead. Neither should increase appreciably due to water ingression (with all else being equal), but a wear metal could increase from abrasive kitty litter ingression. An increase in silicon is similarly conclusive since the silicon (from dust) would ingress by the same means and may even contribute to minor silting, which would be evident from a slight increase in viscosity.

Water may lead to additive drop-out in some cases, so the additive elements could be compared to baseline values. A sharp increase in acid number, if measured, also could be a result from water contamination, but the water may be settling out and not appear in the sample. Other possibilities may exist, depending on which other parameters have been measured or how much historical or comparative data is present.

Just because we don’t have an obvious clue, doesn’t mean we can’t arrive at the likeliest answer. We just have to look harder. People sometimes call oil analysis a black art, but continued perseverance and proper attention will lift the veil and reveal the straightforward science of it all. Keep trying—the truth is out there.

Evan Zabawski, CLS, is manager of training and education services for The Fluid Life Corp. in Edmonton, Alberta, Canada. You can reach him at