X20XEV runs on 3 cylinders

Have the following problem with my Omega-B. Vehicle only ran on three pötten,with the candles I have found that the candle bore of the 4th cylinder is full of water.Has tried the water with the tongue, tastes like nothing, so definitely no cooling water.Have the problem now already for the 2nd time,how does the water get there, has someone already had an idea or this mistake already and removes it,please help me I don’t know any more.