Lets see if we can clear this up.. The pre-facelift E53 uses the M62TU 4.4/4.6V8 with double VANOS. The 04> facelifted X5's use the N62/N62TU with Valvetronic which is a motor and lever system that's sole purpose is to infinitely vary the intake valve's lift and duration. They also utilize VANOS which varies cam timing.

I've always bought non Valvetronic M62 powered BMW's because of the relative simplicity of the valve train. I think intermediate levers and variable intake lift sound great on paper but in the real world of Heat cycles, high rpm, long service intervals etc, they dont hold up well over time. Thats an incredibly complex valve train in the N62 and im amazed it works as well as it does. I'm not surprised though that it makes a little extra noise here and there with all that hardware moving arond in there.

-Ben