Noise coming from throttle body unit?

I don't actually know what the part is called since I'm fairly ignorant. I have an '02 Elantra and noticed yesterday night that is was making a fairly loud noise when I started it. I put the hood up and found the noise was coming from the area closest to the outside of the car nearest the passenger side. I have no idea what the part does but noticed some sort of wiring harness plugged into is as well as a cable coming out that, after following and pulling on it, controls the throttle (I know I sound like an idiot, I am..).

The noise sounding like a motor or something similar that just was off balance or knocking something. It very very repetitive and sounded as long as the car was on. I pressed my hand on the lower part of the unit where a metal cover is (opposite of the throttle cable side) and it was quite warm (hot). That may be normal, but I made note of it anyway.

Any advise you can give me as to what is going on with the car would really help. I plan on calling the dealership ASAP but I'm doubtful they'll be open tomorrow since it's a holiday (who knows though!). I just don't want to do any worse damage by driving it in the meantime, or get stuck in the middle of nowhere. I had planned on going to a rather remote location tomorrow but have cancelled those plans for the time being.

Thanks for your responses and help, I greatly appreciate it.