I have developed a really loud growling noise in the dash of my 03. Its not the heater fan. It kind of sounds like one of those mini tire compressors you plug into the cigerette lighter. Has anyone else had this problem?

 

It may be a small vacuum pump, that is mounted o the firewall, under the hood, just behind the glove box. When you hear it, most folks will say you have a vacuum leak, but I hear mine only when it's cold. I figure it's just the pump not liking the colder temps, as a leak isn't going to be healed every spring.