My 4.4 202 X5 has had no major engine problems...knock on wood. I have 144K on it but I keep it well tuned. I did dent the transmission pan that caused a shifting vibration (as the trans oil heated it did not draw properly from the bottom of the trans oil pan, but was my fault for the dent). Fixed that and life is good again. I have had other things go out like an AC module and the infamous pixels on the radio display but just smaller items so far.