Hello people, come from the Mercedes Forum of so please do not stone immediately. The Twingo of my younger sister causes problems. The heating just does not get warm even after 30 minutes drive. The blower runs on all stages however no heat. Have looked in the balance tank, the content looks like “carrot juice”. I guess the heat exchanger is rusted and therefore dense. Can someone support this thesis or maybe has a different tip?How difficult is it? the change?Have changed everything on the car, springs, brakes, Lima, cooler, OT-Geber…. But where is the heat exchanger sitting? Thanks for the answers.