What Oil Analysis Reveals About Your Engine

How to get and interpret an oil analysis for your diesel engine


We've all heard that if you give a diesel good clean fuel, keep it cool, and stay on top of the oil changes, its life span in a boat can be as much as 10,000 hours.

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Michael Redmond
Michael grew up sailing on his family’s Lapworth 24. As a teenager, he spent two summers teaching sailing at a summer camp on Catalina Island. He has cruised Mexico and Alaska and raced in Los Angeles, San Francisco and Annapolis. He built a Pooduck Skiff which is a small plywood sailboat. Over the past 20 years, Michael has captained charter boats in the US, the British Virgin Islands and Croatia. He holds the necessary certifications to captain boats throughout Europe. Michael is a cabinet maker by trade. His current boat is a Vagabond 43 which he bought and brought up from Barra de Navidad Mexico. That boat is being refitted for world cruising in Oxnard, Ca.


  1. Potassium is not used in all or even most coolants. You would have to test the coolant to make a connection. Coolant analysis is another, related topic. Exhaust-to-coolant leakage problems can often be detected more easily that way as well, due to changes in the coolant.

    Another source of coolant contamination is leaking cylinder sleeve O-rings or sleeve perforation. Was a nitrited coolant used through the life of the engine? Google diesel coolant cavitation liner.

    But the lack of glycol makes a coolant leak seem less likely.

    A good summary. I ran an oil and coolant lab in a former life.

  2. The test appears to be reasonably priced. More questions arise as to what you do with this information and the expertise of the individual telling you what it all means. I’m not sure your neighborhood mechanic would qualify and surely charge many times the cost of this test to act upon the results. I see it somewhat like medical tests I have taken where even my doctor depends on a specialist to interpret the data.