A knocking noise from the valvetrain has been a complaint with the VQ37VHR engine on the G37.  What happens is that the after an oll change, the engine is noisy from the top end.  At first Nissan didnt know what was causing the problem but when the oil was replaced with genuine Nissan oil the problem stopped.

Apparently the DLC coating on the cam followers needs a ester synthtic to stick to it.  There are rumors of $200 oil changes at the dealer, anyone know this to be true?  Do you simply have to run a good qualty synthtic or do you have to run special and expensive Nissan oil?

Yes, there were some complains of valve train noise, as most oils are too thick when cold (even syntethic) so when the lift  changed the oil did not get there quick enough, the use of esterbase oil takes care of the problem and it is expensive at 12 buck a quart even for the DIY crowd, the noise is only heard by very sensitive persons and it only happens once in a while, but if it is your toy, you will notice, so far there has been no reports of any damage from the use of regular oil and i have seen some engines with more than 50k miles on them

Is the rumor that you have to use only the super expensive genuine Nissan oil true?  Ok can you use any ester based sythetic oil like Motul 300V.

There is a bad rumor floating around that V6 Nissans can only have the oil changed at the dealer for mega dollars.

As far as i know, no other oil meets the latest API standard  (i think is SM) but the owners manual does not recommend any particular oil, and you can go to any dealer and get the oil and do the oil change yourself

I got a confirmation that the Z version of the engine does not use the DLC lifers that require special oil.