Moin, Today when driving, the radiator fan went on, and no longer went off. I saw a lot of shock after a while that the water temperature indicator instead of at 15:00 was about 13:00. So very high above the red area. Stopped, engine off, bonnet. Nothing indicates a particularly hot engine. No water vapor, engine top and thermostat housing are hot, but you can touch it. Hose from the thermostat housing top to the cooler warm, b im cooler cold – cooler is cold. Presumably: thermostat (changed a few weeks ago) defective. So always let cool for a quarter of an hour, drive for a few minutes, let cool until I am back home. A 30 min distance covered in more than 2 hours 🙁 But: always when the ignition is switched on, the cooler fan starts immediately, the water temperature indicator goes to 15:00 clock and after a few seconds coughs again to 13:00. New favorite position. Even after the E I stand at home for 2 hours, immediately the radiator fan goes on after turning on the ignition and the pointer climbs after a memorial break at 3:00 pm to its 13:00. Thermostat removed, placed in a glass and boiling water on it. It opens. So not defective. New theory: It was outside about 4 degrees, nice cool for the engine. If the water temperature sensor shows too high a temperature, the cooler fan goes full, the engine is cooled down, thermostat shuts. Cooler is But the needle points to the moon. Question: is the culprit the coolant temperature sensor? Or what else? If what?? And: Does anyone know the values of the sensor? I assume it is an NTC and there must be somewhere a list of the temperature resistance pairs. And: Does anyone know how the needle normally behaves when it gets too hot? Does it rise slowly? And to where? And one more thing: I have read that the 15:00 display of the Tem peratur needle is good for about 60-110 degrees (covers with my VW T5: ’90 degrees’ position at 73-110 degrees). Is there a tell-tale (<- 3x 'l' is actually quite sick, makes it fun when writing) for too high water temperature, or does an engine overheated due to non-opening thermostats die an unnoticed death (if you don't happen to see the needle) ? Many questions, I know. Thanks in advance... I hang a picture from the temperature indicator.