Is an oil temperature of 120°C normal for a BMW X5?

[StKaleb]

A BMW 5 Series oil temperature of 120°C is normal for a short period, but if it remains at 120°C for an extended time, it is abnormal. Under normal circumstances, the working oil temperature of a BMW 5 Series car engine is generally between 70°C and 90°C. Poor lubrication: The component most susceptible to high temperatures is the engine oil. Excessively high temperatures can lead to increased oil evaporation, faster oil consumption, and thinning of the oil under prolonged high temperatures. This makes it difficult to form a proper lubricating film in areas requiring lubrication, resulting in increased friction and accelerated wear of internal engine components. In some cases, dry friction may even occur. Carbon buildup: Excessive temperatures can cause gasoline and engine oil to form carbon deposits and even sinter. Some of these deposits can directly affect combustion, leading to reduced vehicle performance, while others may enter the clearance between components, accelerating wear and even causing engine parts to seize. Increased mechanical loss: Excessively high temperatures can cause the engine to lose more power, with this energy being dissipated as heat, leading to a gradual increase in fuel consumption. Additionally, poor engine cooling can shorten its lifespan to varying degrees. An engine frequently operating at high temperatures may fail prematurely, making repairs impractical.

[VanColton]

When I used to drive a BMW X5, the oil temperature was usually around 100-110°C. 120°C does feel a bit high and not quite normal. I've encountered similar situations before, usually caused by the cooling system struggling to keep up with heat dissipation during long summer drives or traffic jams. If the temperature stays high like this frequently, it can affect the lubricating properties of the engine oil and accelerate engine wear. I suggest you stop and check whether the coolant level is sufficient, if the fan is working, and how long it's been since the last oil change. Don't rush to drive fast—it's best to find a repair shop for testing to confirm there are no issues with the radiator or oil pump. For safety's sake, don't let small problems turn into major ones. This car is great to drive, but it requires careful maintenance, otherwise the repair costs can be quite high.

[McWilliam]

The oil temperature of the BMW X5 reaching 120°C is noticeably high, as the normal range is between 90-110°C. This could indicate an issue with the cooling system, such as a leaking water pump or a faulty fan, or it might be due to overdue oil changes affecting heat dissipation. I recommend you stop the car immediately to check the oil dipstick and radiator cap, ensuring the fluid levels are normal. Note any temperature variations during driving, such as whether it rises more during high-speed driving or under heavy loads. Don’t overlook this—schedule a professional inspection promptly to prevent engine overheating and component damage. Avoid sudden acceleration while driving, as maintaining a steady speed can also help with cooling.

[SanNora]

An oil temperature of 120°C is slightly high, as the engine's designed normal operating range is 90-110°C. Elevated temperatures may reduce oil effectiveness and accelerate component wear. Potential causes include blocked cooling circulation or an overloaded air conditioning system. Regular checks of oil quality and coolant condition can prevent most issues. In such cases, switching to synthetic oil or upgrading cooling components might help, but it's advisable to first consult a technician for proper diagnosis.