Just thought I'd update this thread as I have been having engine issues now for almost a year, the DME throws no codes whatsoever, I have checked for vacuum leaks, replaced CCV valves, replaced MAF etc... but to no avail, still having sluggish acceleration, lagging in gears, loss of power etc... Symptoms seemed to be temperature related, also exhaust noise was increased considerably at times with very poor engine power.
Regarding the VANOS on the N62, apparently its pretty reliable, and due to its vast difference in design over the earlier piston variants I would agree. Technically any fault with the VANOS, either sticking or complete failure would surely result in errors in the DME reported at camshaft too much or too little advanced etc...
This lead me onto the theory that if the DME 'thinks' everything is fine i.e. its requests x degrees of advance and the position is reached then it must be the information its receiving from the engine sensors.
If the camshaft sensor is slow to respond to the pickup disc on the camshaft then the DME would think the camshaft is somewhere where its not. However the DME would be none the wiser.
Therefore I pulled the two sensors on bank 1 and found them heavily coked up with burnt on flaking oil deposits, one of the connectors was filled with oil! the outside of the harness is dry, closer inspection seems to show oil seeping through the sensor itself. I cleaned the sensors in degreaser dried them out and refitted, this time reversing them so the INLET sensor was fitted to the EXHAUST and visa versa to see if this made any difference. (all 4 camshaft sensors are identical).
Well... the difference is incredible! lots of low end torque and no lagging at all when accelerating from a cruising speed!
Im convinced this is the cause of the issues I have been having and bear in mind the DME reports no codes and INPA shows the camshaft positions as being correct! The loud exhaust noise I imagine was because the exhaust valves were being opened too early during the power stroke.
I will clean up the other bank of sensors at the weekend and see how it goes, I will most likely replace all 4 when I strip the engine in the spring.
Anyway, anyone experiencing similar issues, check your camshaft sensor connectors for oil and try swapping them around to determine if the symptoms improve.
Last edited by stuartjohn24; 12-31-2012 at 04:13 PM.