add to your code:
Code:
action tank_controls()
{
 var e_pressed;
 ....
     if(!key_e)e_pressed = 0;
     if(key_e & e_pressed == 1)
     {
       e_pressed = 1;
       start_stop_eng();
     }

}

for the sound,track and tank example i recomend you to study bulldozer demo wink

The smaller the bug, the harder it is to kill.
_________________________________________
Forklift DEMO (3dgs)