So, I have my 07 G35 Sedan. And when I'm at a stop light/stop sign/stopped...I notice that my engine has a noticeably rough sound to it. However, when I press in the clutch, the sound goes away and the engine is virtually silent.

Now, I don't think something is necessarily wrong, I'm just curious as to why this is. I don't remember this happening on my last car... or any other car for that matter.

 

Are you sure it is not the flywheel?

 

Sounds like you are experiencing the dredded flywheel chatter which is inherent with our 2nd Gen 6mt's (and some 1st Gen) when in neutral at a stop. Hope Infiniti enginneers built a fix for the newer G models. I just tune it out.

 

flywheel chatter?

is that something that needs to be fixed or is it just a minor nuisance.

 

^more of a nuissance, had this on my old car, chatter comes from the release bearing (or "throw out" bearing in some cases). it's not harmful, not requiring a fix, just a bit of a nuissance.