Alright Acurazine,

I just noticed this problem couple days ago.
I noticed in RPM's 2-3.5k the engine starts to whine whether it be in drive or park. I notice it more when I'm in gears 1-3 as after that the drone of the ATLP takes over the cabin.

So then I noticed sometimes the whine would go away and then come back.

Final observtion I made coming into work today was that the whine was not present when the AC/heater/fan was turned OFF. Only when ON.

Another thing I noticed this past summer was that the passenger side could not produce air as cool as the driver's side, even if the setting was set to "Lo."

The heater for both sides work fine.

I'm not sure if the engine whine and the passenger side cooling capacity is related, but the whine is definitely becoming a concern.

Another thing to note is that I recently changed my oil from regular 5w-20 to Mobil-1 5w-30. And MAYBE I put in the wrong octane gas in my most recent fill. I'm not sure if that would play a roll.

Search tells me it could be the sepertin(?) belt?

 

Serpentine belt or the tensioner. Have someone give the car gas and try to pin point where the noise is coming from. You can also take the belt off and listen while the car is being rev'd