I drive an 03 2.0l dohc mazda protege. So far motor wise Ive only done 5.0 wires connected to bosch iridium plugs and an aem CAI. very recently (past 3 days its seems), Ive noticed that primarily around the end of the day or at night, when Im driving I can be in low gear, yet hear a whining noise. It doesnt sound like metal against metal but more like possibly a belt. It can happen with low or high rpm's it doesnt matter. I know its not my intake because my intake has a deep throaty sound, and this is almost the opposite with a sort of high pitched whirring. I've heard it once before my alternator went out, but I just recently put in a new one, so im pretty sure its not that. If you guys can respond with what you think asap, I would greatly appreciate it.

mmm that sucks dude...does the sound change with the rpms? does it matter if any accessories are turned on? a/c etc?

I do drive the car pretty hard, and I have put roughly 5,000 miles on it since i purchased it in january at 43,640. Though even before and after I added my tach, I have rarely taken it above 4k rpm. it seems to get higher when i give it more gas. Its weird though, it happens alot more towards the morning and earlier at night. I think it has to do with the temperature. During its normal daily use it sounds fine. The sound is similar to when I hit high rpms with my motor and how it can make the sort of working to get to that next rpm noise, which when I do it is barely noticable (kind of the trail end of the sound my motor makes) except now its a bit more distinguished from the regular sound of the engine. As for accessories, no I tried turning going through all the settings and turning it off, it still does it. Im really fearing that its transmission or worse motor. If its just a belt thats no worries, but still, worried....

It sounds like it could be the belt but I would also check everything else that is conected to the belt. like water pump, A/C, smog pump, etc. When it is making that noise, pop the hood and listen to the motor.

the odd thing that it isnt constant though. Its only when Im pressing in the gas.

Remove the alternator belt and run the car. Listen for any "whirring noise". If it's gone, it's either the alternator or one of the pullies involved. Do the same with the other belt (but don't run it for too long since this one drives the water pump).

I took off the belt and it doesnt seem to be those, but I believe I have found out what might be it. It appears during the day (very faintly) at certain rpms I hear what sounds like something being spun around in a can. I believe I have a spun bearing my friends, which I believe could contribute to the previous noise correct? The only thing is this sound doesnt happen while sitting still, only while moving.

Get out of the car while it's running. Walk around it. It may be your fuel pump. It would increase as you hit the throttle as the pressure regulator allows pressure to increase to match fuel needs. I know on gm cars, hte pumps get really loud before they go out, but you can always hear them. It might be nothing to worry about.

So while idling there is no noise but when there is a load on the engine there's a noise? What about if you are coasting in nuetral?

Usually a spun bearing doesn't allow you to continue driving for very long. But it's not terribly uncommon for Proteges to have bearing issues.

I don't think it is a spun bearing. You would hear that all the time. If it is only while you are moving, I would maybe look into the trans or the CV joints. Do what tom said and coast it in neutral if you still hear it than it is not the motor.

The noise has seemed to die down a bit. I think it is my alternator, I had them check it out but they say my voltage was fine. And that faint scrapping noise is gone. Not sure if it was due to the new oil change, but oh well, heres to hoping all goes well.

I tried the neutral bit to see if hear the scraping but that doesnt seem to be it. It happened when I pushed in the gas to a certain degree.