Rattle On Acceleration!
 

Well the dealer has had my car for close to a week now--and they are having a problem locating the source of this raspy rattle sound under WOT. I have an A/T and it is heard at about 4000RPM on up to redline. They have narrowed it down to a location between the engine and flywheel--anyone else experiencing this? The dealer-Jeff Haas Mazda-Houston- is pretty good; this just puts a crimp in my upcoming travel plans.

Well-they are going to replace the exhaust manifold-apparently as exhaust gases were being forced through the opening it was causing a metal shield to vibrate.

well that didn't solve the problem--anybody have a clue!?

does it happen everytime at wot and only at wot? and it's continuos from 4k up? you hear it all the way to redline and if you shift and keep on wot you still hear it?

What octane rating gas are you using?

hey I'm getting that raspy sound too! but mine's a MT and it only happens at low rpms, it goes away above 3000rpm.... (either it goes away or I can't hear it over the engine sound) and seems to randomly come and go as the car heats up or cools down... guess I'll ask about it at my next service, keep us updated! :)

oh and thanks for the description... I was trying to think WTH describes that sound... and AH HA! "RASPY!" :D

Well--I went to pick up my Millenia S (replace O2 sensor) from the dealer that was working on my RX8 as well--the exhaust manifold did have a leak that they replaced--but it appears the raspy noise could be from a batch of bad gas. I only use 93 octane--however it must have been a bad batch of gas; they filled it up again and the noise appears to be gone--they'll see if its still noisey tomorrow; if not then I'll be back RX8'in.

My bad on the bouncing username--I have registered several times and every time I log in it uses other names--gonna try and re-register before seeking technical help.

just log out and clear all of your cookies then log back in with the name you want to use. then you will only have the one cookie to auto log you back in. end of the bouncing username

Does anyone else have a high-pitched "jingly" rattle that only shows up from about 6000-6500 RPM? It also comes back from 8000-9000, but not as loud (or maybe it just doesn't seem as loud compared to the engine).

I've taken it to the dealer twice, but for some reason, they can't figure out what it is. They told me to not worry about it, cuz it didn't seem too bothersome to them.

Another thing - the rattle only happens with the car in gear. Revving in neutral while parked sounds perfectly fine.

BTW, I've already had the damper recall done. Hoped it would help, but it didn't - although the rattle does seem a little quieter now. Maybe they just didn't do it right?

Any ideas?

I have heard a rattle a few times before at WOT from a rolling start. I also have an automatic. It sounds like a can of rocks being drug from the bumper (which also sounds just like an automatic when its thrown into park from a slow roll.)
Could be the torque converter taking a crap.

The rattle is gone--so try octane booster or 93 octane--cuz it could be bad gas. Still haven't changed the cookies yet tho.

I get that noise also

Me too, some people on the boards say its detentation, or maybe you're using low octane gas. I've tried all different octanes of gas and I still get that noise. Must be california's crappy refined oils.

and I have only used 91 since purchase

well here in Texas it 93; try out some octane booster and see if it remedies the problem.

I hear this exact same thing. I would describe it as a metal-on-metal ringing sound, but it happens at the same RPM range, around 6k. It only happens under acceleration, not if you rev the engine in neutral. Maybe the transmission rather than the engine? I was going to check to see if anyone else has this, so I'm glad I found someone who does. Hopefully it's not a problem, as I was thinking maybe I didn't break my engine in correctly. Anyone else have some insight into this?

BTW, what's WOT? I've never heard this term.

wide open throttle

Yeah, put me on the list with this noise, too. I've noticed it the last few thousand miles as I've become more "in-tune" with the sounds of my car. A high pitched, raspy sort of buzz, almost like a bearing noise, only higher pitched.

I'm actually slightly relieved that others notice it, too. Perhaps the sound of the S-DAIS operating? Or maybe it's just another quirk of the Renesis?

i get it too in canada...i have a mt.....i also have an engine ticking noise to top it off..i always use high octane 91....

My car does this as well. Only I notice that the power seems to drop off or lag when the clicking sound starts around 6k rpm. Does that happen to everyone or is it just a noise?

Concur. Mine comes on just about any RPM under acceleration.

I have the same rattle.. except the other day it happened to be doing it at idle too.. and I went and listened to it.. it sounded like it was coming from the exhaust.. I tried touching the heat shield and muffler to see if I could change the rattle and that didn't do anything... It sounds like it's coming from IN the muffler???

I get the same noise but typically it is in city driving, stop and go, where I cannot stretch out the motor. At the first opportunity to punch it, it makes the noise and power cuts a bit.

Seems like the motor is loading up and the noise and power cut is a result of it trying to clear itself. After a few trips to redline it usually disappears for awhile.

I have AT as well

Man I thought I was the only person with this problem. I hope we find out what the heck it is.