Hyundai Repair: squeeking under engine, wd 40, stethescope

Question
i have a 1997 tiburon and i have squeaking under my engine. i don't know where its coming from. my belts have been changed and tightened properly. i hear the squeaking when i first turn on the car and when im waiting at a traffic light and it gets louder when im holding the brake pedal in at the light. while im driving i can still hear the squeaking but its only a slight noise. what is causing this squeaking?

Answer
It's hard to say.  You can narrow the possibilities if you can identify whether the squeak varies with engine speed.

If you think it might be the belts, you can take a can of WD-40 and spritz a little on each belt.  If the noise changes or goes away when you do that, you'll know the noise is coming from the belt.  

If it's not the belts, it'll probably take some probing with a mechanic's stethescope or similar device to find the offending part.