So, now it’s my turn, too. After having the intensified feeling that the pedals are slippery, I had to find out that the floor mat is wet on the driver’s side, while at the same time it feels a bit oily or slimy. This of course also makes the shoe sole smooth. In addition, the cooling water level slowly decreases. Ergo is probably something leaky on the heater heat exchanger. The often described further symptoms such as constantly fogged windows, fog exit from the fan nozzle n or cooling water smell (we actually smell that?) I did not find out, however. Since we had this topic already a few times, I just read a little bit. According to this instruction the heat exchanger goes without changing dashboards, that is already good. I would only like to ask those who have already done this repair, whether in such cases the heat exchanger itself is really always rot or whether other (simplistic) causes can occur. I see two flanges going through the spray wall from the engine compartment. What is behind it, pipes or hose pieces? How are the inside installed or fixed? Second question: It is possible to do a cooling system pressure test. How about the setpoint? Can all workshops do this, or do I have to go to this? Third question: Has someone got a cheap source for a heat exchanger ready or used such a part (but densely) around are you lying?