What causes the excessive oil temperature in a BMW 523?

[DelAbel]

Both poor heat dissipation from the oil cooler and excessive engine temperature can lead to excessively high oil temperature. The impact of the oil cooler on the oil: During warm-up, the oil cooler absorbs heat from the coolant, allowing the oil temperature to rise more quickly. When the temperature becomes too high, it is cooled by the coolant. This ensures the oil temperature remains stable and maintains an appropriate viscosity. The oil cooler not only cools the oil but also helps prevent oil degradation. Excessive engine temperature: This can cause increased wear between components due to thermal expansion, reducing the engine's lifespan. Additionally, high temperatures lower the oil viscosity, further exacerbating wear between engine parts. Therefore, special attention should be paid to engine temperature during hot summer months. The normal coolant temperature is around 90°C, while the normal oil temperature should be within the range of 95-105°C. A temperature of 110°C is considered slightly high. If the oil temperature is excessively high and the fan continues to operate for cooling after the engine is turned off, it is advisable to have the vehicle inspected.