Help on my car's noise

Hi, I am a new coming. I have a 96 civic LX. These days, when I start the car and pull the acceleration pedal, a click sound like "ka,ka,..." came from the hood. If I pull the acceleration pedal hard, the frequency of the noise will increase. And after about 8 minutes, the sound disappeared. In last winter, when I heard the sound, I ased the honda dealer and they told me it is normal cause the weather was cold. This spring the sound really disappeared when weather became warm. But now it is so warm and the sound came again. Is there anything wrong? Can anyone help me? BTW, my car is 4-auto.

You drive an auto... that is why it makes the "ka ka" sound :lol2:


Need a little more description on the noise.