My car makes a popping or cracking noise when I start it but not all the time. If I hold the brake pedal down really hard it almost feels like the pedal jumps when the popping happens. Sometimes when I driving down the road and hit a bump I hear the popping noise as well. It doesn't happen when I turn and I don't hear a clicking noise when turning. The sound almost always happens when I start it and sometimes when driving. thanks for your assistance!