Method and system for oil dilution control

摘要

Methods and systems are provided for operating an engine in a hybrid vehicle in response to fuel and water dilution of engine lubricating oil. An engine oil dilution counter may be adjusted based on a number of engine hot starts and duration of engine operation above a threshold temperature. In addition, the counter may be adjusted if the engine is started to deplete stale fuel in the fuel tank.

主权项

1. A method for an engine in a hybrid vehicle, comprising:
in response to oil dilution being higher than a threshold while a battery state of charge is higher than a threshold charge, operating an engine to raise engine temperature above a threshold temperature for a duration, wherein one or more of the duration and the threshold temperature is adjusted based on a stale fuel clean-out history.