 With turbocharged engines, the oil seals on the turbocharger may fail, allowing lubricating oil into the combustion chamber, where it is burned like regular diesel fuel.In vehicles or installations that use diesel engines and also bottled gas, a gas leak into the engine room could also provide fuel for a runaway, via the engine air intake.The crank case ventilation of modern road-use diesel engines is diverted into the intake manifold, because ventilating the crank case into outside air is inadvisable due to lubricant mist it contains.