Hello. Can someone give me a tip what I could look at ? The smart just stays cold in the interior. I have read that it could be air in the system that you could let out at the sensor for cool water . But I did not find it . Or you should change the inlet valve . Also I did not find it on the car . Here are some photos of the engine . Under the car behind the gearbox actuator or what that means could possibly be the inlet valve of the water pipe . Maybe someone can give me a few tips . In the manual it is made neither of the thermost inside nor of the coolant sensor . Maybe it lies on those parts below the glove compartment .