hissing noise while i accelerate?? what could that be??

[Five35]

This is a weird noise.... It's like a hissing noise when i accelerate(Almost sounds like the noise you get when you put an intake on your car, like i can hear air rushing in or something.. ).. The weird thing is that it doesnt happen all the time, only 1/2 the time i accelerate which would rule out a vacuum leak or some kind of hole in the airbox. Anyone have any idea what it could be, it's totally baffling me??

[632 Regal]

German snakes?

[Rustam]

This is a weird noise.... It's like a hissing noise when i accelerate(Almost sounds like the noise you get when you put an intake on your car, like i can hear air rushing in or something.. ).. The weird thing is that it doesnt happen all the time, only 1/2 the time i accelerate which would rule out a vacuum leak or some kind of hole in the airbox. Anyone have any idea what it could be, it's totally baffling me??

exhaust leak? perhaps you are missing a nut on one of the pins of the exhaust manifold?