hi guys!

i've owned my aveo for about 5 years now. Almost never had any problems that i couldn't fix.

lately though, my car seems to be making a weird whine/humming noise when accelerating.
Happened once out of nowhere. The Check Engine light came on and turned off after 2 days.
car seems to shift fine? maybe slips a bit going towards 2nd gear, which is when the whining is loudest.
RPMs normal.

This whining noise i can describe as the engine trying too hard?
it's there when i turn the car on, even when it idles.

I changed the spark plug wires since one was shot. Car ran better, stronger, and quieter at idle.
but i can still hear it. the car sounds like i'm pressing the gas pedal at all times.
but again, RPMs are at normal levels.

Fluid levels are all good.

I really do not want it to be the tranny. cause obviously it's costly.

anyone ever experience this or can possibly shed some light on this?

VIDEO: https://www.youtube.com/watch?v=FZIf_qE--Q8 (second half shows actual noise)
NOT MY CAR. mine doesn't sound as bad as the car in this video, but it's noticeable.