If you crank it all the way the power steering pump will make a light humming noise that you can feel in the steering column, but that's perfectly normal on every car and doesn't sound like what you're experiencing. So it doesn't make this noise at all if it's say, 60 deg outside? Has it repeated itself throughout seasons, or did it start this winter? Just trying to make sure you don't draw a causal relationship between cold and the noise prematurely.
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