2005 Pacifica Front End "Hum"
 

The noise sounds like the engine is racing (it kicks in pretty loud at 40mph and continues up to 60-70mph, and then stays all the way down to a stop). SO it doesn't feel cyclical.

It's as though something has suddenly gone out of balance.

The trans shift pattern is fine. RPM's don't go past 2300. It operates very well.

It sounds a bit like loud tire/road noise, but the tires a fine (and I rotated in case I couldn't see a belt issue).

It comes with a vibration that can be felt in the steering wheel and both pedals AND the cooling fans get really loud when sitting at idle (I can't tell if that's related at higher speeds).

It's a front wheel drive, too.

Any ideas?

May have had same symptoms
 

Had a hum from alternator area, it ended up being a pulley.
Don't know if its similar, but it's way cheaper than most other guesses I was given.... Even chrysler replaced the alternator before I freaked on them and said, no, the sound is still there! Ended up being the 125 dollar pulley.