PID 5C°C
Engine oil temperature
Engine oil temperature. It warms up noticeably more slowly than the coolant (PID 05): when the temperature gauge already reads normal, the oil is still cold — which is exactly why you do not rev a cold engine. Once settled, the oil usually runs a little hotter than the coolant; if the gap is large and stays, look at the load and at the cooling system.
What is normal
Usually 90–110 °C once warm; above 130 °C is a reason to stop.
These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.
We have a detailed piece on thisOil pressure: codes P0520, P0521, P0522, P0523, P0524
Step by stepHow to tell whether the thermostat is to blame
How it feels behind the wheel
The same fault shows itself in different ways. Each sign below says what to look at in the live data.
The temperature gauge is climbingThe needle goes above its usual place, there is a hot smell from under the bonnet, and the heater may blow cold on a hot engine.The heater blows coldThe engine is warm but the heater blows cool or barely warm air. Sometimes one side is warmer than the other; sometimes it only gets warm while driving.The air conditioning will not come onThe button presses, the light comes on, but there is no cold air. Sometimes the compressor clutch does not click when switched on; sometimes the cold disappears only in heat or in traffic.Slow to warm up, the heater blows coldThe temperature needle sits low for ages, the cabin stays cold, and on the motorway it gets worse. Consumption rises noticeably.The cooling fan runs all the timeThe fan roars right after starting and does not stop even on a cold engine or in frost.
How to see it
In CarScan: the Live data tab, «Start polling». The app asks the car several times per second, draws a graph and remembers the highest and lowest value of the trip.