A conventional internal combustion engine controls the amount of air supplied to cylinders of the engine via a camshaft. After intake, the air may be mixed with fuel for combustion. For diesel engines, the engine speed (revolutions per minute or RPM) is controlled by the amount of fuel injected into the cylinders for combustion. After the air/fuel mixture is ignited, the combustion gases exit the cylinders through exhaust valves.
In an embodiment, a diesel engine may experience uncontrolled condition wherein the operator reduces fuel intake to decelerate the engine and oil is consumed as fuel in the cylinders. The oil may be transmitted to the cylinder from a crankcase in fluid communication with the cylinders. Specifically, a conduit or breather pipe feeds into the cylinder to vent the crankcase. In the embodiment, fluid, such as air and/or exhaust, can carry oil mist from the crankcase into the air intake via the breather. The engine can run on this oil mist in addition to or instead of fuel in the cylinders, thereby causing the engine speed to increase as this oil is taken in as extra “fuel”. The increased engine speed includes increased piston revolutions which can draw more oil mist from the crankcase and into the engine. In some cases, the engine reaches a point where oil is drawn from the crankcase and shutting off the fuel flow into the cylinders will not stop the engine.