Jack up wheel.
Use a jack stand.
Grab wheel at 12 and 6. Shake.
Grab wheel at 3 and 9. Shake.
If the wheel moves something is wrong.
Movement at 12 and 6 means bushings or ball joints.
Movement at 3 and 9 means tie rods or steering coupler.
Since its on one side only I'm going to eliminate the steering coupler.
Get someone under the car to watch with a good flashlight if you're having trouble identifying what's wrong.
Everything else is just a guess till you go test. This is an easy test, go do it, now! Don't post till you have as its just a waste of time to keep guessing.
Sent from my Nexus 7 using Bimmer App