Diagnosing a bad wheel bearing can be difficult sometimes since the sound seems like it emanates from the entire car rather than one corner. A bad wheel bearing will also sound better or worse depending on if you’re loading weight on or off it in a turn while driving. What I recommend doing once you start to hear that distinctive howling sound from a bad wheel bearing is to jack your car up and check each wheel individually for a specific grinding sound.
Another thing other than listing for the sound is to grab your wheel and try to pivot it checking for side to side slop. You really don’t want to drive on a bad wheel bearing for too long as the wheel bearing could be heating up much more than normal and things can go downhill from there…
In this video I’ve taken the wheel and brakes off to show exactly what your bad wheel bearing could sound like. If this wheel bearing were OK, it would not be making that ugly sound when moving.
Check out our writeup on an E30 5 lug swap conversion to see what the wheel bearing job involves if you plan on tackling it yourself.