mpali5

Hey guys I own a 06 550i w/sport package. I have noticed a strange noise, sounds like a (machine gun like sound or like injectors ticking very loud) when accelerating between 1100-1400rpm in every gear. I was convinced that it may just be the injectors making more noise under specific load range but now i am not sure. But the weird thing is that if I press on the snowflake for the a/c the noise completely disappears throughout the rpm range. Also my car idle is at 500rpm but when I turn on the a/c the idle goes up to 700rpms.

Anyone experience similiar problem? Any ideas?