check ur AC bearing (pully) or fan belt
i had the same problem with my car.
i checked the air intake hose and it had a crack.when accelerated, the whistling sound was made due to the air entering thru the crack.
i replaced the hose and its perfectly fine.
just put little graese on belts & it will go ( mech. says by oil belt may remove aotomatically due to low friction, graese is best option )ideally change all your belts with new & geniune
