Hi together, I hope you can help me with a few tips.My Caddy (STS Bj 98 with 245,000Km) has a temperature problem, behind which I have not yet come. Here is a description of the problem. I often travel on highways. When I drive the Caddy speed and then come into a slow column (80-100 km/h) the temperature pops up so high in the shortest time that the DIC brings the message “engine overheated / idle recommended”. When I drive on after a few minutes (possibly more than 110 km/h), the temperature goes down. A few days ago, I drove comfortably over country roads. After 10 km (very comfortable driving, engine was certainly not really warm) then at a traffic light also the temp. briefly went up. After the further drive the temperature has normalized again. Which is certainly still important: When the temperature blows up, only cold air comes out of the heater ystem. When I travel comfortably at 150 km/h, nothing happens. Nor any problems in the city traffic (stop and go….) The problems do not always occur by the way…… I don’t believe in the cylinder head screws in this case. The cylinder head seal should also be OK. No bubbles in the cooling water, No water in the oil or vice versa. I am happy about any reasonable tip. Greetings from the district HN Martin