Snowman1234

2015 Silverado 5.3. Same issue. It was my battery. Had turned over slow a couple of times over the last month as I hadn't driven it every day. Today turned over slow. Pulling up to a location I was was wondering where this noise was coming from, like is someone using a blower, or is there a big truck near me? Turned off my truck and got out to hear it coming from my truck. Same noise on my drive home, stopped at O'Reilly, changed out the battery, temp gauge at 160 all the way home (was 50 today here) thought that was strange, but got back in it an hour later and drove around, no fan noise and temp back to just under 210 like normal. In my case 100% the battery.