I have a 97 850 with almost 100k on the clock. While driving over bumps, small and large, i can hear a knocking noise from the engine area. I have replaced the upper strut bearings, thinking that they were worn out or loose. The noise still persists. The engine moves quite a bit while grabbing it on the motor mounts, though I've read that this is normal. Which if any of the motor mounts wears out around 100k? I will be checking the ball joints tomorrow to see if they are worn. I do get a little bit of vibration at speed above 65mph too. Hopefully this is something I can fix....soon.