What are the reasons for engine oil dilution?
1 Answers
Below is an analysis of common situations regarding engine oil dilution: 1. The common occurrence of oil dilution is generally observed in the cold northern regions, primarily due to low temperatures which significantly slow down the evaporation of liquids. The heating rate of engine oil and the radiator also slows down considerably, while the engine injects additional fuel to maintain operation. 2. This results in some of the fuel entering the cylinders not being completely burned, which then adheres to the cylinder walls. During combustion, the high pressure forces this unburned fuel into the crankcase, explaining why there is a gasoline smell in the engine oil. 3. As the engine temperature rises, this gasoline would normally evaporate and be drawn through the PCV valve into the intake manifold, then re-enter the combustion chamber to be burned and expelled. However, due to the cold weather, the evaporation process takes longer, and the gasoline remaining in the engine oil does not evaporate, leading to an increase in the oil level.