In the past month I have spent a good deal of cash replacing some sensors to pass inspection and replacing an oil pan I cracked going over an unexpected speed bump. Things were good for a few days, but a week ago I started noticing an awful sound coming from my back left wheel.

You can start to hear the noise at about 25mph and it gets louder with speed up until about 60 at which point road noise starts to drown it all out. The best way I can describe it is that it sounds like a small airplane does when you see it in the sky, like a constant whirring/buzzing.

I'm not sure what the issue is. I replaced both back rotors, pads and calipers a month ago with no problems. Tires are new-ish and I rotated them two days ago. Noise didn't move or change. There is no play in the rotor side to side or front to back and the noise seems to go quieter when I turn right, and louder if i swerve left. The rotors don't seem to be abnormally hot on one side either. Does this sound like a wheel bearing or what?

PS. Had my ABS controller rebuilt and replaced it like a week and a half ago. Noise is definately coming from the rear drivers side tire. I had another person drive and put down the rear seat to confirm.

 

Anyone have any ideas on this? Noise is getting worse but still no play in the rotor. The noise is loud enough that it easily drowns out the sound of my engine at speed.