weird noise

i installed a cold air intake on a 98 expedition 4.6. it been on a few days now , and a weird noise comes from the engine compartment, it sounds like a low pitch whistle. and will happen just as i touch the gas. i'm thinking one of the clamps might have loosend up. anyways , its snowing and 20 degrees outside. and was just trying to narrow the posibilities down so i don't freeze. i hope its just a loose clamp from the cold air. oh and it does sound like its coming from around where the throttle body is. hope someone has an ideathanks