Good day, wanted to change my spark plugs after about 70 tKm. Turning off went relatively well, but then it was getting harder and harder. I guess that I had to turn out the candles with about 50 Nm of torque. When the first outside was the shock, the thread has eaten down. See picture in my profile. I then tried the second, the same problem again. The third candle can be turned out even harder, is still half inside. So now my big question: New candles turn in and is good, or better first cut the thread? Thanks for the answers. Candles and rod ignition coil was previously renewed by the workshop. Candles could be solved relatively well at the beginning, but then…. Car ran 210 tKm, actually up to the rod ignition never had problems with it.