Be part of the largest student community and join the conversation: My car is making a whistling sound?. 7L F250 with 117,000 miles. Track your pet’s location in real time, plus monitor health, fitness and more for total peace of mind. I'm not sure what to call it but when I idle its fine. Take your time and remove the turbo, hold onto the turbine shaft and remove the compressor wheel with an open end wrench. Fuel economy seems really bad - about 15MPG. what would cause a high whistling sound from under the hood on the right side? 3 Answers. How to Whistle Loud. A heart murmur is a sound caused by blood flow within the heart. I get exactly the same very slight audible turbo whistle from cold, it only happens from overnight cold and by the time I have done 1.