Hello all, I drive a Seat Leon 5F 2.0 TDI, 184 hp (engine identifier CUNA). EZ 12/2014 About half a year ago (168,000 km) the car has gradually lost cooling fluid. After a mechanic’s sighting the water pump including timing belts was changed, as the water pump was leaking. After the change the car has lost no cooling fluid. Since about 2 weeks (180.000 km) the car loses with longer distances (over 100 km) and high speeds (over 160 km/h) a lot of cooling fluid, so that the balance tank was completely empty. I filled up with G13. Now I have read in the forum that the heat exchangers often hit and it leads to coolant loss. I turned the heater in the car to see if the driver side is warm as the passenger side. With a temperature meter (infrared) I measured a temperature difference of a little 10°C. With warm engine on the left approx. 60°C and calculated When the engine is cold, the difference was clearly felt with the hand, when the engine was warm, the difference was hardly noticeable with the hand. Can it be that my heat exchanger is cut by the G13 (flocking) and therefore I lose coolant? I have now also been to a free workshop and the mine of the charging air cooler has to be changed, that problem often occurs after a change of the water pump with timing belt. The mechanic has with a camera re. offer amount: 1.500€ So far I have found that for short distances as well as for longer distances with lower speed (400 km max. 150km/h) no trace fluid is lost. Now my questions: 1. Can it be due to the heat exchanger, even if the temperature difference is now not very clear? 2. Is it due to the charge air cooler and then it has to be replaced completely for 1.500€?