If an engine has both low oil pressure and high oil temperature, what might be a probable cause?

An engine exhibiting both low oil pressure and high oil temperature can indicate several underlying issues, but a leaking oil dilution valve stands out as a probable cause. When the oil dilution valve leaks, it can allow fuel to mix with the engine oil. This can lead to a reduction in the oil's lubricating properties, resulting in lower oil pressure because it cannot maintain adequate lubrication under load. Additionally, when fuel dilutes the oil, it changes the oil’s viscosity, often leading to higher operating temperatures. This combination of low oil pressure and high oil temperature indicates that the oil is not performing as it should, potentially leading to engine damage if not addressed promptly.

In contrast, worn bearings typically result in low oil pressure, but they may not directly cause elevated temperatures. A clogged oil filter can restrict oil flow, leading to pressure issues, but it would not usually be the primary cause of increased temperature without additional factors like insufficient oil. Insufficient oil capacity could cause low pressure and might lead to overheating, but it wouldn't directly involve the dynamics of a leaking dilution valve which introduces fuel into the oil system. Thus, the context of engine operation and oil characteristics provides a clear pathway to understanding why a leaking oil dilution valve is the most fitting cause in this scenario.