In this article, we look at the subject of oil temperature and oil pressure and show why it makes sense to monitor these parameters. We have prepared our DUCATI DesertX and DUCATI Monster 1100 EVO to show you how to install our CUMPAN Cockpit Assistant, which can be used to monitor these parameters.

First, a brief technical overview of why it makes sense to keep an eye on the oil temperature and pressure. In most vehicles, the cooling water temperature is determined as standard and taken into account by the engine control unit – especially for cold starts. Some vehicles also have an integrated temperature display for the cooling water. However, the engine oil heats up more slowly than the cooling water and therefore optimum lubrication is usually achieved later than the indicated cooling water temperature suggests. Once the oil has finally reached operating temperature, the engine block is usually also sufficiently warm and the uneven expansion of the individual engine components caused during warm-up has been eliminated. Logically, the engine should only be fully loaded from this point onwards.

Furthermore, the viscosity of the oil changes with the temperature. In a test on our DesertX, we determined the following values at idle speed:

At an oil temperature of 23°C we have an oil pressure of 7 bar, at 60°C it is still 2.7 bar and at 95°C only 1.6 bar is left.

If the oil temperature is low and the oil is viscous, the oil pump must build up a higher pressure in order to pump the oil. On the other hand, a high oil temperature can cause the lubricating film to break off because the oil is too thin. Temperatures above 130°C should therefore always be avoided.

And when we talk about viscosity, we must of course also consider the oil pressure: Because the oil pressure is directly related to the oil temperature. When the oil is cold, very high pressures are created, sometimes over 10 bar depending on the Motorcycle. And when the oil is hot and the RPM is low, the oil pressure can even drop below 1 bar. As the oil pump is driven by the engine, the delivery rate is directly related to the RPM of the engine. This means that more oil is pumped at high RPMs, which increases the oil pressure. If we now monitor the oil pressure, this can provide us with a lot of important information:

If the oil pressure is very high, then the engine is (still) cold – e.g. also an issue in winter – and should naturally be subjected to little load.

• If the oil pressure is unusually high even when the engine is warm, an oil line may be blocked, i.e. the oil flow is obstructed.

If the oil pressure is very low, there may be various reasons for this:

• Either the oil is too hot and the pump cannot build up sufficient pressure
• Or the oil is already aged and has been diluted with fuel over time during operation, which of course makes a premature oil change necessary.
• There may also be a mechanical problem with the engine. This means that you should not continue driving, especially if the oil pressure is suddenly significantly lower than usual. This is because there may be a defect or leak in the lubrication system, which can lead to serious engine damage.
• Finally, it can also happen that the oil pressure drops completely or pulsates. This may be caused by the oil level being too low. The oil pump then sucks in air and can no longer deliver enough – or evenly – oil. Logically, the oil level must then be checked urgently and the oil topped up if necessary.

This briefly describes the different scenarios that can occur on the engine in connection with oil temperature and pressure. Depending on the vehicle, intended use and location, it can therefore be very useful to keep a close eye on the oil pressure. And attention should always be paid to the oil temperature, if only to warm up the engine optimally and thus protect the individual components from unnecessary wear. For this purpose, our CUMPAN has an integrated shift light, which gives visual feedback at an adjustable threshold value of RPM and motor temperature that the RPM should not be increased any further. We usually set a threshold value of 60°C here because, in our experience, the oil is already sufficiently fluid at this value and already provides very good lubrication performance.