Hum / harmonics
 

I have had my car since the end of april and b/n 1st and 2nd gars driving normal i have notice a hum kind of like the sound that u would get blowing into a soda or beer bottle? any clues? Its going into the dealer for a check engine light so i will have them take a peak at that too.

Does the sound occur at a particular rpm or rpm range?

Sounds like the diverter valves are leaking.

For sure the divertter valves, I had the same problem, I've since changed out the OEM Bosch valve for A pair of Forge billets (also adjustable vacuum connection very handy in the cramped engine bay) If installing these use stainless hose clips instead of the factory clips - they are much easier to install.