i took a mini road trip over the weekend and while cruising at highway speeds 55mph+ i would hear a humming/throttle noise coming form the engine every time i hit the accelerator.

the noise was consistent and was noticeable.

anybody know what this can be?

 

You heard a noise every time you hit the accelerator? Could be the engine...working.

But seriously, you'll have to elaborate a little more. If you're going 55 and you hit the accelerator, the engine will get louder because the RPMs are increasing. Exhaust noise would also get louder. So you'll have to elaborate on what made this particular noise different or unusual and be more specific about what you heard. I personally don't know what a "throttle" noise is.

 

Do you have any "odd" noises at idle?

 

The two noises people bring up most often on the 2IS are 1) a whining type noise, which has been described as normal and related to the timing chain (as opposed to a timing belt), and 2) a ticking sound, which is due to the nature of direct-injection engines. I've seen nothing about a humming.

 

Or it could be a feedback loop from your stereo? Do you have something plugged into the AUX port that's also being charged through the cigarette lighter?