Once my car is warmed up is started to make a high pitch chattering noise once I hit around 2.5k rpms and up.
When I press the clutch and rev the car the sound completely goes away.
So it seems to only be there under load.
Car doesn't really make noise when cold.

(It sounds like a high pitch clatter/chatter noise if that makes sense)

50k miles 6mt also tranny sounds grumbly on idle.
Any ideas?

 

Mysterious noise? Goes away with the clutch depressed?

Throw out bearing? (Lots of possibilities)

 

Trans input shaft.

Typically noisy, worst on the JK41 trans behind the VQ35HR.

Pretty much a known issue with no real solution. Just gets worse until it stops completely - about the same time you’ll need to replace the transmission shaft (but more likely, the whole trans). Sounds facitious but fact of Z life.

EDIT: Should note this doesn’t mean it’s dying. Just something you have to live with and keep an eye on it. The reason the sound goes away when pressing the clutch is because you’re applying pressure (enough to dampen) the vibrating/chattering shaft.

 

Guess I better have a 370z trans ready to go when this one goes potentially.
Thank you! You saved me some worry haha

 

I don’t see any reason this shouldn’t work as everything lines up, so to speak. But know that the VQ37VHR uses what’s known as an EA series transmission - one with and one without Synchrorev (as found in Sport snd Nismo 34s.) This feature, however, might make it firmware incompatible with HR/JK-trans models. Speculation only.

Last time I looked, a JK transmission for HR was the same price as a CD00A (nee CD009) for non-HR.

But in the meantime, just bank this info for when you need it.