I HAVE THE SAME PROBLEM IN MY 1990 325IS. I HAVE HEARD ALOT OF PEOPLE TELL ME THAT IT IS THE SPINDLE NUT ON THE COLUMN BUT WHEN I CHECKED IT WAS NOT LOOSE. WHAT REALLY IS THE PROBLEM IS THE UNIVERSAL JOINT ON THE STEERING COLUMN WHERE IT MEETS THE RACK . CLIMB UNDER YOUR CAR AND SEE FOR YOURSELF. A PERSON I TALKED TO CONFIRMED THAT IT WAS THE UNIVERSAL BECAUSE HE CHANGED HIS AND THE RATTLE WENT AWAY. I HAVENT CHANGED MINE YET BUT I WILL REAL SOON.