pjomara

Have 1.6 Diesel Superb. If I go driving directly to the motorway (2 min away) and drive at 120 Kmh, the car overheats. Well the needle goes into the red (~125°C) and the overheating alarm comes on, but the temperature of the oil is only about 90°C. After slowing down or stopping briefly, the engine goes back to normal and even if drive 140kmh after that it never overheats for the rest of the journey. Same if I do 10 min of normal driving first before motorway, no overheating. It's as if the car needs 10 min of warmup before it can do 120kmh otherwise it'll overheat. Any ideas of the cause? Had recent oil change. Coolant levels also topped up.