I would like to know why my car is making noise when the engine is idle, but the noise is silence when I pressed the clutch ?
With the lack of information you've (haven't) provided, there is only one thing which I can think of which might be causing the noise you are describing, and that is if the main bearing in the front of the transmission is going out. When you push in the clutch pedal, the transmission is disconnected from the engine and is therefor not turning. When the transmission is in gear and the clutch engaged, the front bearing will not usually make any noise due to the torque applied to the main shaft. That is at least at first until the bearing gets bad enough to be making noise all the time. If this truly is the problem, it can only be solved by taking the vehicle to a mechanic for a transmission rebuild.