ABYC Diesel Practice Exam

What is a likely effect of water contamination in the fuel system?

1. Ignition failure

2. Corrosion and rust

3. Higher fuel economy

4. Reduced engine temperature

The correct answer is: Corrosion and rust

Water contamination in the fuel system can lead to corrosion and rust as a significant effect. When water mixes with diesel fuel, it can create an environment conducive to the formation of rust and corrosion within metal components of the fuel system. This can adversely affect fuel pumps, injectors, and tanks, leading not only to deterioration of these parts but also to further operational issues. Additionally, the presence of water can disrupt the combustion process, leading to incomplete burning of fuel, which can result in various performance issues. Optimally functioning fuel systems require clean, dry fuel to ensure efficient operation and longevity of the engine. In contrast, mixing water with fuel does not lead to ignition failures directly; while it may interfere with engine operation, the primary concern remains the damaging effects of corrosion rather than outright failure to ignite. Water contamination also does not contribute to higher fuel economy or reduced engine temperature, as these outcomes are typically linked to a well-functioning and clean fuel system.