When i start and accelerate from stop i can hear a gurgling (like a hungry/upset stomach or like sucking the last bit of milk through a straw). I dont know is this is related but it started the day after i filled the gas tank up half-full. Temp gauge is normal. The van is due for a oil change in 800km. I looked online and most seemed to say that it is radiator fluid related. Any other ideas or assistance... Thanks