I recently heard a knlnking type noise on my rear passenger wheel.
Any advise on what it could be? I was thinking the shock is going bad.

It's more than likely the top shock mount. Very common failure.

Stephen

Yes, I 2nd that. Get it replaced before it tears the sheet metal in the fender.

It could be ur exaust or muffler, check it, if its very wobly then my freind, its ur muffler. I had the same problem in my 325e, ever since i got the muffler replaced, never heard it again :)

Check the wheeel lug nuts for tightness.

I had a hum like thump, i thought it was the tires but it was a wheel bearing,,
not easy to replace it was a press on,, we beat it off with a brass rod.
$100.00 and had to drop the drive shaft. just an idea.

Does it happen when you are driving over bumps?
When you press your brake?
Bolt in tire?
All the time? Sometimes?
Could be several things, all of which need attention I would think?
More details please.