My well-maintained '07 V70 T5 FWD with 306,000 miles has developed a noise that I've been unable to pin down. It seems to come from the left front wheel area, and sounds like an owl hoot with each wheel rotation when pulling away from stop, and fades after a few car lengths. I put the car in neutral, jacked up the wheel and spun it by hand, but heard no noise of any sort. M&S tire pressures dead on 35psi. Front brake pads at 4mm due for replacement in 4,000 miles. The noise continued before and after the recent replacement of the right front axle (I forgot to bring it to the mechanic's attention).
What should I be looking at? TIA