My dryer makes a buzzing noise when it starts.

The dryer makes a buzzing noise when it starts but works. However, after using it to dry two loads of laundry, when I press start for the third load, it buzzes and won’t start. If I wait about 30-45 minutes it will start again and works BUT after another two loads, it buzzes and won’t start. I always empty the lint trap after ever load and have taken the entire lint trap out and cleared out a lot of lint deep inside but that didn’t help. Any idea? The dryer is only 6 years old.