Humming Noise between 40mph and 50mph
 

Today I bought a 2000 911 Convertible Automatic Transmission with 25k miles and discovered a humming noise coming from the rear that begins every time I hit 40 mph and stops after 50 mph. It is much louder than the engine or muffler sound. It also stops as soon as I release the gas pedal or place the car on cruise control. So it only happens when I am accelerating between 40 mph and 50 mph. Any and all of your suggestions will be greatly appreciated.

This section of Pelican is for the air-cooled, pre-1989, non-turbo 911s. You will get a better answer in this section for your 996: Porsche 996/997 Forum - Pelican Parts Technical BBS

Thank you.