Recently developed a tapping noise on my 09 X with the 3.8L. I believe it's coming from the driver's side. It went away (I believe) after an oil change to only come back. I tried Liqui Moly but that didn't seem to help. It doesn't seem to be there 100% of the time and seems to not be as present when I let off of the acceleration and onto the clutch. Oil level is fine. I used Penzoil Premium High Mileage Full Synthetic 5W-20. No loss of power whatsoever.
I'm considering selling/trading, but obviously I can't like it is. Other than that noise and a CEL for an O2 sensor (B2S2), which I have a replacement for when I find the time. Otherwise, it's in very good shape.