I didnt find the correct place to post this. Sorry. My girlfriend has a 2000 Mercury Cougar V6. And it just started about a month ago. When you start the car up it makes a strange humming noise. Most of the time it does it when its cold outside. I popped the hood and tried to pin pointwhere the noise was coming from and it seemed to be coming from the frontdriver fender (that area).Oil level is fine. Trans fluid isfine. Only has 77k miles on it. Thanks everyonefor the help

 

Starter couldbe notdisengaging properly. Check trans. fluid color also. The cold could be enacting a switch (such as if you put on cheap aftermarket air horns - I had a set of those that switched themselves on overnight in the cold and melted the compressor). Honestly any switch is possible to have failure. Many parts are never tested sub-zero unless you are in Canada, Russia(U.S.S.R. - or whatever their new name is) and most extreme regions where engine block heaters are normal. Listening closer will help a lot. Also a manual specific to your car may help identify part locations and facilitate repairs (since it may not do it for the mechanic in a heated shop environment).