Servus! I have the following problem with my 92er B4 Quattro NG. My Audi has recently become extremely hot (warning lamp starts at approx. 140km/h) when I drive away and, for example, when I am standing at the traffic lights. On the other hand, sometimes the temperature drops from 90 to approx. 50-60 degrees within about 15 seconds during the ride. Sometimes it runs quite normal as if it were nothing and remains stable at 90 degrees. Actually it can no longer be possible: Cylinder head gasket Thermostat cooler water pump the two temperature encoders that sit at the front of the flange at the head the encoder for the fan recirculation that hangs at the back of the valve lid in the air I have already aired forever, only water comes out. Heating also gets warm. The coolant indicator and the AI are also OK. E-fans are also starting. Slowly it gets really interesting, I really run out of ideas. Who has an idea? MfG