I got to blow a little bit of snow recently here in MN. While doing that I was reminded of a question I had last winter that I never got around to asking...
With the tractor running at full throttle and the snowblower on I occasionally hear a curious noise. It sounds sort of like a radiator fan spinning up, staying on for a random amount of time, and then going away. This happens randomly, but fairly frequently. Tractor was nowhere near being hot at the time, though the engine was fully warmed up to operating temp. I didn't think the x7-series tractors have electric fans.
I don't recall this noise in the summer, but the only time I run wide-open in the summer is mowing and I always have hearing protection or noise cancelling headphones on while mowing, so I may just have missed it.
This is 100% NOT the sound of the snowblower auger or impeller. That sound starts when I hit the PTO switch and stays constant. Being that I'm blowing snow at the times this happens I'm not in a position to get off the tractor to look closer or open the hood.