Ok so I posted about a strange sound I was having when I started my car and that it only happens on cold days. So I have been trying to figure out what it is. I’m going to try to give a better explanation of when it makes the sound. I start the car and it idles at 1,000, then it will kick down to around 750 after about 10 seconds or so and this is when the sound starts. It doesn’t make it at 1,000 but right when it changes and goes down to 750, the whistle/whine sound starts. Also if I rev it I will hear it just for a second when I let of the gas. When the car warms up the sound is gone. I’m now thinking it could be my idle pulley, what do you guys think?