help-sudden knocking/vibration front left wheel
 

I have an 01 xc70, 122k. Today, a vibrating noise started in the left front wheel area after driving about 5 miles. I heard something faint when I first took off, but it became very obvious on the highway. The frequency increases/decreases with speed change. The car doesn't shake, but it's pretty loud. Stuck my head out the window while driving slow and heard a rubbing sound. The noise seems to go away during braking. At low speeds it's a clunking/knocking sound. We had the tires replaced three weeks ago. The lug nuts were so tight that it took the mechanics 45 minutes to loosen them. Don't know if this is related in any way. I have zero car fixin' experience.
I'm afraid to put my kids in the car, but I gotta drive. Any advice is sincerely appreciated.

Make sure the lugs are not loose now.

holy cow...totally nailed it. one lug nut is totally missing, another is loose. does this mean my tire has been wobbling and causing damage? did sears strip the threads perhaps? anyway, thanks for the spot-on diagnosis.

There might not be any damage. They might not have torqued them properly and they came loose. I would tighten them back up and have it checked.