New fan motor noise on Denali. Can't figure out what it is.

ggmcandy

I have a 08 Denali that we bought this past winter. Run fine, mechanically sound w/ no problems. Since it's been warmer when I start it, it sounds like there is a louder fan motor coming on. It's noticeably louder. I shut off the whole heat/ac control thinking it was a fan motor and it was still running. I have no clue what this running motor could be. Anyone have any ideas? It sounds like it runs fine and has a job to do but I can't nail down what it is and its driving me nuts. It's very noticeable when you start the car.

skyisthelimit

How about the cooling fan clutch? Does the fan noise occur when the car is in motion?