I had the starter replced on my wifes 89 535 almost exactly two years ago. The starter they put in was told was a new bosch unit.($249)! When starting this morning, the starter sounded like an electric drill. Not grinding but a winding sound. If you just tap the key it fires right up. I called the shop who replcaced it, and he said he only warranties for 1 yr. If I keep driving it this way, what may the outcome be?