Does your 8 make a 'grinding' noise when the clutch is not engaged and the car is in neutral, but the grinding stops when the clutch is pressed in? YES or NO?

Yes and no. Yes, it makes the noise; No, it's not the clutch, it's the gearbox input shaft bearing.

yes, it makes the noise, regardless of the tecnical source of the noise. but it's not really grinding, more like 'whirring'.

Yeah, I wouldn't call it a grinding really.

For me, it's kind of a gravelly sound.

i had my car in for the oil pan replacement today and i didnt mention the bearing sound because i think its ok.

Yes it sounds like a bad pilot or throwout bearing but it is the input shaft bearing like fastrunner said. It's quite noisy on the 3rd Gen RX-7 and many Mazdas.

Yea, mine makes that whirring noise. Time to call the dealership!

Hey guys, what's with the "well it must be a problem" problem so evident here?

Surprise! Cars make noise. In fact we all love car noises, esp. the 8's engine and exhaust e.g. So this is the 8's trany noise. Big deal. Sure this particular gravely sound may be a unique to our 8s, but how about, wonder of wonders...it is just normal...for an 8.

If it's anything really wrong... how come no one has reported their transmision grrrriinndd its way to destruction... while in neutral?

LOL It's just a little noise!

And if it isn't, Mazda just fixes it!

My 1981 RX7 made the same noise for all of 21 years I had it, even after two clutches and new through-out bearings. It is nothing to worry about and is normal.

Thanks guys. That's what I was trying to find out. How many people have this "noise" (which by the way, does not bother me), and if it is something we should be worried about! Sounds like it is normal.

My car is surprisingly quiet when in neutral (once the excess gas in the rotars are burnt off). Sometimes I even forget the car is on.

yup. Mine sounds like a choo choo train. Actually it just goes...

"Chugga chuggua chugga chugga chugga chugga chugga chugga".

Yes, and it did so from day one. That was four months and 3500 miles ago. Noise is still that...no change of any kind.

I thought that the Mazda goes HHMMMMMMMMMMMM. I remember the commercial from when I was a kid.

Now, back to the noise. It is not the pilot bearing. If the clutch is not being stepped on then the pilot shaft and the crankshaft are both spinning together and the bearing is not doing anything. What the noise is probably from is torsional vibration. In that case the transmission gears rattle or growl in neutral and possibly under no/low load conditions in high gear. The dampers in the clutch disc usually dampen most of the engine's torsional vibration out before it reaches the transmission gears, but in some cases the dampers (usually springs) are not enough to totally eliminate the noise. It shouldn't harm anything if that is the case.

I just took mine to the dealer today for this very same grinding thing. The sound is exactly how you described it. I thought I was going crazy (and the shop helped perpetuate this a bit). I had two techs take a look at it at different times (one in the morning, and one in the afternoon). Each determined it was a normal noise. I am very relieved to hear folks in this forum share that they have this same noise, and that it's nothing to be concerned about.

The second guy did perform 2 recall items, a "dynamic dampner" heat shield recall, and a air bag harness recall. Might want to see if your RX8 needs these..... SMACKAY

as a point of reference

http://www.miatanet.com/garage/tsb/s003_95.html

have it, and i luv it

Old Miatas do it...

New Miatas do it....

Even brand-new RX-8s do it...

Let's do it -- let's make that sound...

apologies to Cole Porter

All my Mazdas make that sound. It's normal. Don't worry about it.