Engine Oil Filter Important for Contamination Removal. (I&T's Maintenance & Repair).

Q We still have a few customers who remain skeptical of the need to change engine oil and filter as often as the operators manual recommends. When we try to explain that contamination is one good reason for servicing these two items at the recommended interval, they ask what are these contaminants

A There are two major sources of contamination: external and internal. External includes dust and dirt that are breathed in with the combustion air in spite of the air cleaner, as well as dust and dirt that enter through the crankcase breather, even through it also has a filter. Internal contaminants include unburned fuel that goes down past the piston rings during warm-up and during cold-weather operation; water vapor, a product of combustion that condenses and collects in the crankcase; fuel soot, which results from incomplete burning of the fuel; cooling water or antifreeze that may leak into the crankcase; and oil oxidation that results from high-temperature operation.

Melvin Long's career included new-product development for John Deere and hands-on management of a family farm. Now retired, he continues to tackle technically-oriented projects, including publication of a book on hydraulic system diagnostics.