I got my G35X a month ago with 99850 kms on it. The car is a complete BEAST and i love it. The only downside is poor fuel consumption and another issue of mine which is a weird sound which the car only makes at idle and that too not all the time, sometimes and it comes and goes.

I am attaching a link and would be really helpful if someone helps me as i am afraid that if it turns out to be an engine issue, its gonna cost me alot!

The sound is much more louder towards the end of the video around the mark of 9 - 10 seconds.

 

I don't really hear anything out of the ordinary. Can you describe the sound and any particular conditions where it comes and goes?

 

 

 

I don't hear it either. Google "Timing chain rattle G35" and see if it's the same sound. If it's not it's probably something minor like a heat shield vibrating.

 

Sound seems to be external. Use some wd-40, oil or whatever your brand on all the pulley shafts while the car is off. Don't get any on the belts. You want penetration where the pulley's spin on their bearings. A/C clutch included. My guess is one or both belt tensioner pulleys.