I have a 2004 Monaco 34 ft. It is a diesel pusher. Purchased in May of 2017. At purchase it had 29,000 miles - was kept in a garage by the original owner. When I purchased it I had a local mechanic (Alabama Diesel Service) service it from front to rear and also new tires all around. My wife and I traveled on short trips during the summer of 2017 and traveled about 4,000 total miles. On our last trip (Sept 2017) we began to hear this noise up front that begins softly and grows louder as you speed up and become ear piercing and as you increase your speed and then goes away. The only way we can describe the sound - it is like the sound when a PA system feeds back on itself. It will not do it at the same speed each time but it does come between 40 mph to 55 mph. Since September I have noticed it does not depend on the tempertature. Here in Alabama it has been heard during the winter months and also now during the warm months. And then at times when I drive it (Each Friday I drive it a min. of 100 miles) I will not hear the noise at all. Example: Two weeks ago I drove it to Birmingham and back (about 200 miles) and never heard the noise. Then this week I drove it and the noise was there again. It is like I am traveling at 40 mph and as I speed up this sound starts and keeps getting lounder until it is ear piercing. Then as I speed up it goes away. Has anyone had a similar problem?