Last year in June my crankshaft pulley failed on my '05 Cooper S. The rubber section between the inner and outer parts of the pulley detached. The end result was an overheated dead MINI. I replaced the pulley with an ATI unit. All was good, that is until December when the head gasket went. Which I suspect was related to the overheating when the pulley went in June. So another learning opportunity on MINI construction becomes available. I completed repairs to the head and added a couple of mods while I had things apart and all was good, that is (stop me if you've heard this before...) until the alternator pulley started to make a awful racket just before it fell off. The point of all of this is I should have seen the cascade of failures coming, since the engine over heated I should have pulled the head and had it checked when I did the crankshaft pulley. Likewise since the alternator is driven by the serpentine belt and that was wobbling all over the place while the crankshaft pulley was failing I should have been looking at that as well, but... So when you have a part fail check everything around it it may save you time in the end.