Generation IV Internal Engine - Strange sound

After my H/C install I am noticing a strange whistling noice that sounds like its at the rear of the car.

It is very faint and it doesnt always happen. It almost sounds like a tiny little turbocharger spooling up or something.

What is this? Fuel pump? Im not sure.

turn your radio off. on my car for whatever reason the one of the speakers behind me somewhere makes that noise when accelerating.

just power the radio off and see if it still makes the noise. if it still makes the noise then thats a rearend/ gear problem or something.

could just be the rear whining


:::EDIT- whoops you have a fifth gen....i dont think my electrical problems will help you :D