What indicates a successful fogging of an engine?

A successful fogging of an engine is indicated by a visible oil coating on internal parts. Fogging oil is specifically designed to protect engine components from corrosion during periods of inactivity, and applying it correctly results in a thin layer of oil that clings to the surfaces within the engine. This oil acts as a barrier against moisture and contaminants, which can lead to rust and deterioration.

When fogging is effective, you should be able to see this oil coating, which signifies that the engine parts are adequately protected. The other options, while related to engine performance and condition, do not directly indicate the effectiveness of the fogging process. For example, an engine running smoothly might suggest good overall health, but it doesn't necessarily reflect the success of the fogging itself. Similarly, increased fuel pressure or the absence of smoke could pertain to other engine conditions or adjustments rather than the fogging's protective qualities. The presence of the oil coating is a direct and clear indicator that the fogging has achieved its purpose.