I have a knocking noise, can anyone help?

There are struts on the front that in-close, hold the coil spring. That strut turns as you turn right or left. The coil spring has pressure on it sitting in the cups. So normally it is the bottom of the coil spring that will give, slide, in the cup it is resting in causing a popping sound. Struts also will make a creaking noise that comes from the protective boot around the shaft of the strut. One could try and get some grease along the bottom of the cup for the spring to be able so slide easier so it does not pop.