I have here an Alfa 33, which has a bit of coolant loss (about 250ml on 500km). I have the car now after almost 16 years standing very carefully over 500 km again “began in” The car had a problem because the radiator fan was wrongly wired and pulled only warm air out of the engine room. So it is quite possible that the right cylinder group in the summer in the city traffic became very hot, because he did not get fresh air. RELD CO2 test bought and see it becomes green, which suggests CO2 in the cooling circuit. There is no emulsion in the oil, the oil cover is clean and there are no white clouds from the exhaust. The colleagues (@Diplomat28E and @Go}][{esZorN) here in the forum had advised to let the ZKD be replaced prophylactically with such a low coolant loss, especially since it could also be micro-cracks in the cylinder head or that it has spread. See https://www.motor-talk.de/…lkreisla uf-z-b-reld-t7752126.html?… Now I had informed myself whether K-Seal vlt. could be used to fix the problem. K-Seal’s support reacted surprisingly quickly. They thought that the loss of coolant was so low that they could not assure that K-Seal really got to the point where it was damaged. Either after 10 warm-up and cooling phases K-Seal was successful or the leak was too small. Does anyone have any experience with it? Would you start an attempt like this or do it with it? Replenish cooling fluid until the damage becomes greater.