Question 17 UFIV01 - Chief Engineer - UFIV

The Correct Answer is A **Explanation for Option A (Full-flow filtration):** Full-flow filtration is the correct answer because, in this system, **100% of the lubricating oil being pumped to the engine bearings and vital components passes through the filter element before reaching those points.** The illustration, MO-0181 (assuming a standard representation of diesel engine oil systems), typically shows the oil pump drawing oil from the sump and pushing it directly through the main oil cooler and filter before it enters the engine's main oil gallery. This ensures that all contaminants that could damage the engine are removed instantaneously from the main flow path, providing immediate protection to critical moving parts. **Why the other options are incorrect:** * **B) Sump filtration:** This term is generally used to describe the location of the oil intake screen (suction strainer) in the oil pan (sump), which is designed to prevent large debris from entering the oil pump. It is not a complete filtration system description. The primary filtration occurs after the pump. * **C) Bypass filtration:** A bypass system (or auxiliary system) only filters a small percentage (typically 5–10%) of the total oil flow at any given time, using a high-efficiency filter to remove very fine particles and soot. The oil is often returned directly to the sump, bypassing the main oil gallery. This system is used *in addition* to, but not *instead of*, the main full-flow filter. * **D) Shunt filtration:** This term is sometimes used interchangeably with bypass filtration or partial-flow filtration, describing a system where only a portion of the oil is filtered, but it is not the standard industrial term for the primary filtration loop that protects the engine immediately.