Method for taking into account the outgassing of fuel from the engine oil of an internal combustion engine

Abstract

The invention deals with a method for operating an internal combustion engine with engine oil as the lubricant and a fuel supply by means of direct injection, wherein an air number (lambda) of a fuel-air mixture supplied to the internal combustion engine is determined. Provision is made in the method according to the invention for the internal combustion engine to be transferred to an operating state with higher fuel consumption, when a low air number (lambda) is detected in driving conditions with a high percentage of fuel ingress from a crankcase ventilation system into the fuel-air mixture. By means of this increase in the fuel requirement, the fuel, which exited the engine oil into the intake air of the internal combustion engine, can be combusted; and an increase in the exhaust gas emissions by means of incompletely combusted fuel, in which typically hydrocarbons and carbon dioxide arise, can be avoided. In a warm-up phase of the internal combustion engine, the fuel, which ingressed into the engine oil, can thus likewise be combusted, even if under certain temperature-time conditions, particularly in the partial load operating mode and during idling, more fuel is present in the fuel-air mixture than is actually required for operating the internal combustion engine.