Two days ago, a knocking sound started to be heard, coming from the front right tire. At the beginning, I thought it was a stone or a screw in the wheels but I checked them, and there was nothing there. When lifting the car with a jack and turning the wheels using the hands -the car turned off and in neutral- the same noise appears. The speeds do not have any problems, they are not stuck nor do anything out of the ordinary. The car does not jerk either. What might be wrong? Hope you can help me.