Lately I have been hearing this noise from the car. It is a grinding, hum. It does it when the engine is cold and @ 1800 rpm around 40mph and @ 3100 rpm around 75 mph... Its consistent at this point in this RPM range.

It also makes this same noise when I first start the car. Very cold engine, at a stop light.. hummmmm/grind.. Pretty awful noise. Cant pin it down in Park. Only in gear will it make this noise.

I will also add that the noise sounds metallicy...

 

Does it still happen once the car is warmed up to normal operating temperature? It sounds like a heat shield rattle to me, mine does it as well. I even ripped off the bottom part of it and the piece at the top still does it.

 

+1

 

Yeah. It does it still once it's warmed up.... Whats odd is that it is scary consistent at those RPM ranges.

 

Go under the car and check your heatshields. That's most likely what is causing the annoying grinding noise at the certain rpm. I had the same problem and just removed the old rusted heatshield right where the headers connect to the exhaust.