Hello everyone I have an 04 manual 6 speed RX-8. I am experiencing a weird noise (I am attaching a ) when in neutral idling, where it sounds like there is just rattling coming from the transmission tunnel. It will randomly happen while in neutral only. It is not consistent but usually happens at least once or twice a drive.

I just got the engine rebuilt and streetported about 1500 mi ago along with an Excedy stage 1 clutch kit, except I used the throw out bearing from a turbo 2 transmission. I did that because I know they are notorious for causing issues in that kit. I haven’t experienced any other issues, I have plenty of other mods but I imagine nothing that would be related to this. I’ve been experiencing this since I got that done, before the rebuild I never had this happen but me and my builder couldn’t really pinpoint where it was coming from and now I have moved far away from him so I am trying to fix it myself.

I also recently replaced the reverse switch as it was leaking, but when I refilled the tranny there was barely any fluid lost. I doubt the short period of time that it was leaking caused any issues.

Any ideas or suggestions are appreciated.

 

Sounds like a heat shield to me.

 

You can take it to a muffler shop, have them tell you what's wrong with it, and either let them fix it, or DIY.

I had one rattling on an old truck I had.
The shield around the tack welds rusted out.
I tightened a bunch of long metal hose clamps strung together around it and it never rattled again.

 

It does but only problem is I don’t have any. I have a full aftermarket exhaust. The sound has stopped now as the engine has remapped and I am almost done breaking it in but I think I need engine mounts.