When pulling away a minute or so after starting the car and accelerating, around 20mph I hear what sounds like something dropping up toward the front of the car. It isn't affecting any performance or anything, I just wonder if this is a normal occurrence. I just got my '11 maxima s a few weeks ago.

 

I might be the fluid in the heater core. If the car is completely cold the liquid in the heater core will slosh around until the car warms up and starts circulating coolant. Have heard noise In my 02 and fathers 3500 Chevy