So ive been having this problem for the past several months or so. Basically everytime the car is in idle there is this scratchy sound that is very noticeable from inside the car and as soon as you press on the clutch the sound goes away as if air passage is blocked. this sound also is noticeable when driving, only goes away when clutch is engaged.


On a side note, my rx8 drives pretty rough during a cold start past 3-4k rpms and and bogs out after that if you go full throttle. after a little bit of driving and warming of the rx8, the issue goes away but only starts bogging after 7-8k rpms.

New cat, plugs, coils, maf were all installed in the past year. My mazdaspeed aem cai looks really greasy around the end of the tube that leads down to the front bumper. Figured maybe i should get this cleaned? not sure the condition of filter

Been reading the forums quite often but just havent been able to find much. Wondering if anyone can give me any insight thanks in advance

 

A video might help identify the noise. Based on the description, could be the throwout bearing, but beware that even whe healthy this car has a noisy transmission.

As far as the bogging, definitely check the filter. Are you losing oil quickly?

 

If your sitting at idle with your windows down and hear a rattling type sound that only goes away when you push the clutch pedal in, its more then likely the throwout bearing. Most of these cars seem to start having that problem at around 100k miles. Not really anything you can do about it other then having it replaced witch includes dropping the transmission, so should change the clutch as well since I'm not positive that you can even by a throwout bearing without the clutch kit.

For your bogging issues you might want to look into the ssv (secondary shutter vavle) it may be going bad causes the bog. Goto advance auto, oreilys, etc...and use their obd2 scanner. Just because you don't have a check engine light on doesn't mean that their might not be codes stored on some problems.

 

My throughout bearing is going out, so I am replacing my clutch and slave cylinder. My kit came in today, Marry Christmas to me!

 

Good Move Pyrium, a Merry Christmas to you and your RX8 !

 

I just had the same issue now my car won't crank. Here is a picture of my throw out bearing

 

I just had my entire clutch kit replaced and slave cylinder too. I wasn't able to do the work myself, but the guys at AutoSport here in Lewisville, TX did the work. I did however replace my ignition coils on my own. My car feels brand new again. 97k miles and she is humming along just fine. The old clutch was damn near fried. The coils were bad too, but with the new ones installed she is as smooth as a hot knife through butter. Gosh I love this car.

 

Sounds like input shaft bearing to me