I started hearing it today at low speeds. I was at a stop.and turned the wheel to see if that did anything to produce the sound and it didnt. At higher speeds, I cant hear it, just at low speeds.

What comes to mind to check? Strut mounts? wheel bearings? worn endlinks? How to test any of those?

 

I would check the tie rods, control arm bushings, ball joints, sub frame bolts, etc to start... I agree the upper strut mount could also be a culprit.