71-Camaro-98

iTrader: (17)

So I have had this creaking noise slowly growing on me over the past 2 months or so. It normally only happens between 1600 and 2300 RPM on random occasions but today it did it at idle when I fired it up this morning (it also seems to happen more when it is cold). It sounds like a really old creaky floor and it does shake the car a little. I am guessing that something is loose somewhere but I am not sure where. I am either guessing my exhaust or the drivetrain, but I have not messed with either anytime recently. Any suggetsions??