An Engine's Defense Requires A Good Offense

Actions to take to avoid potential problems

You have likely heard the metaphor, “You are what you eat,” and interpret it as needing to eat good, healthy food for one’s body to be healthy and fit. For engines to stay healthy and fit, they must be serviced properly with quality products. Today’s advanced engine technologies can be more susceptible to premature failure and damage from contaminated or substandard products being introduced into their systems.

Therefore, it is important that fleet owners and operators be aware of potential problems and take action to protect their investment in engines by establishing a good offensive plan designed to reduce downtime and help keep fleets on the road.

Because problems that may arise with gasoline engines are usually different in nature than issues with diesel engines, it’s unlikely that there is one “magic bullet” that will protect against every problem with every engine manufacturer. Problems with diesel engines likely won’t be addressed properly using products or remedies for gasoline engines and vice versa.

Two areas where a good offensive plan especially pays off are the quality of fuel used and the antifreeze/coolant used to help protect engines. Numerous engine failures can be traced to degraded fuel or coolant quality.


Today’s fuels are specialized products that are made to burn cleaner and produce lower emissions. They must meet mandated regulations to help reduce atmospheric pollution. To comply with these laws, refiners must use various processes that change certain properties of fuel. After manufacture, fuel must be protected from contamination.

The presence of moisture or water in fuel, whether gasoline or diesel, can create a multitude of problems and seriously damage an engine. There are plenty of opportunities for moisture to contaminate fuel after it leaves the refinery, including through transportation, storage and handling and exposure to humidity.

Regardless of how it gets into the fuel, water causes problems and protection against fuel contamination is imperative.

Gasoline is susceptible to water contamination due to its chemistry. More than 95 percent of gasoline at the pump contains ethanol in about a 10 percent concentration. Ethanol is a compound used to oxygenate gasoline so it burns cleaner. However, ethanol readily absorbs water from its environment and high water concentrations may cause ethanol to separate from gasoline.

A concentration of ethanol and water in solution is heavier than fuel, and if introduced into an engine’s fuel tank, it is probable that fuel filters may become obstructed or the engine won’t run properly. Minimal moisture contamination can be treated with a pour-in water-removing additive.

Engines at high risk for moisture contamination, such as marine engines or those in prolonged storage, may also benefit from use of a fuel stabilizer treatment added to the fuel. Fuel stabilizers help preserve the quality and color of fuel in storage.


Water contamination in diesel fuel is a common problem. Diesel fuel holds more water in suspension than gasoline, which wreaks havoc with water separators, fuel filters and fuel injectors. Filtration is generally required at several points of distribution to help ensure water doesn’t reach the engine.

Moisture also hastens microbial and fungus contamination of diesel fuel, resulting in slime from bacteria growth. Moisture also increases solids contamination, intensifies corrosive properties and will shorten fuel filter life.

In colder climates, water in diesel fuel can freeze and plug fuel lines and filters. Moreover, a portion of diesel fuel is made of wax (paraffin) molecules. The more wax in diesel fuel, the higher the energy value. However, too much wax in fuel can cause cold temperature plugging and fuel flow problems.

In response, chemical manufacturers now produce additives that help prevent cold weather problems resulting from wax and ice, and produce biocides to fight microbial and fungus contamination. While biocides help prevent and kill bacteria and fungus in diesel fuel, use only as necessary as they may not mix well with other fuel additives.

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