 The N62 (X5 4.4) is notorious for a valve stem deal issue which is a $4000 repair. For more evidence search "X5 white smoke cloud." This happens around 130000 miles, which I just reached. Avoid this model at all costs, and stick with the 6 cylinder which is a much more reliable vehicle. Such a shame and a waste of money in my case. The car is awesome with the exception of this fatal flaw.