Rumbling noise when cornering - what is it?
My car has 45K miles (E90 M3 stock suspension, EDC) and a whole bunch of track days (eight events this year alone). Driving back from Ohio today, I noticed in West Virginia where I-77 has a number of curves that on every right hand curve there is a rumbling coming from the left front wheel (driver's side) that is speed dependent. It's not a steady rumble but a whop, whop, whop deep low frequency rumble that has a cadence that is speed dependent. The sound goes away when going straight and there is no noise coming from the right side nor when the road curves to the left.
I jacked up the left front corner today and tried to see if there is any play in the wheel and there is none. I removed the wheel and I am unable to feel any play when I try to wiggle the disc back and forth. The rotor spins somewhat but there is a fair amount of drag from the pads that you can't really spin it and listen to it freewheel. When I changed to my regular street tires, the noise is still there ( I had my track set on the trip).
I was thinking I had a bad left front wheel bearing but now I'm not so sure. It would make sense as most tracks you go in the clockwise direction and the left front is going to take most of the load. Is there any other way to test the bearing or do I need to look elsewhere for the source of that noise?