Hello. am new here and have a question to the specialists. At my TGA I have very high pressure in the cooling system and thus water loss over the overpressure valve. In the balance tank bubble in the stand gas 1 euro pieces large air bubbles. Cooling water is clean, no soot or anything else to see. Compressor heads were renewed about 80,000 km ago by the previous owner. What do you think, AGR module, head seal or is it possible that the compressor heads already have cracks again? .480 XXL SZM, EZ. 1/05, 610,000 km, AS Tronic with Intarder greeting Thommi