mrkinn

i sometimes notice ( when i dont have the radio blasting ) a certain kinda knock or a rattle when i accelerate my 8. has anyone else had this problem its still under warrenty, but i was wondering if anyone else has heard this that might be able to provide me with more info if i have to take it in. im fairly certain this doesnt happene everytime?? can anyone please help

thanks

TeamRX8

iTrader: (25)

no, what octane level gas are you using?

mrkinn

just regular unleaded gas

RedRexNJ

That may well be your problem right there.

TeamRX8

iTrader: (25)

you should use mid-grade or higher, premium from a quality name brand source is preferred, I personally won't run anything less than premium in my RX-8

the manual states that regular is ok as long as it's 87 octane, the problem is that you have no way of verifying that the fuel coming out of the nozzle meets this requirement even though the pump may state 87 octane, there is a lot of shiznit gas being sold due to the current pricing issue, so you could well be getting low octane fuel,

I'd recommend that you read Page 4-2 in the Owners Manual

mrkinn

i will start putting a higher grade in and see if i hear a difference... has anyone else had this problem or heard it???? or anythiny other ideas thanks all

mrkinn

also how do i make a pic small enought to fit on this page mines like 150 kb has to be less then 100 i think how do i shrink it???

therm8

this sounds like a common complaint here. Any particular rpm range where this occurs? Mine has a rattling sound on occasion (same one everyone else has) under acceleration, and it's not due to octane. There's a couple threads dealing with this (if it is the same type of rattle). try a cearch for "rattle acceleration," maybe it'll help.

TeamRX8

iTrader: (25)

I have never heard rattling or knocking of any sort with my RX-8

for resizing the image, google the net for a freeware program called "Irfanview"

max5roadster

Under light acceleration, some, including myself, can hear a rattle like noise. This is a combination of the resonance of the intake and the various intake port operations. I would suggest as others have and switch to a 91-94 octane gas for the next tank.

HeelnToe

Yup, same sound here. I'm using 93 octane.

Sigma

Could just be a heatshield somewhere. At a certain RPM it resonates just right to make an annoying noise.

guy321

Could be a heatshield, especially if you have an aftermarket exhaust. Things move and expand when heated up that can cause rattling.

I experienced this with my borla. I ended up tying up a part of the heat shield with a cable and releasing and re-tightening the clamp while the exhaust was fully hot.

Worst case is that some of your cat broke off and is rattling in your exhaust. I don't think detonation in the rx8 sounds like knocking. When I had it, it sounded more like a belt squeal, but there could be more than one kind I guess.

zoomzoom_8

i have just noticed the rattling also, usually in the very high rpm range 7 -9, 1st - 3rd.

Of course detonation is what i immeditely thought but I ALWAYS run at least 91 and usually 93. Sounds similar to detonation on a piston engine but not exactly.

So I am asking for opinions from everyone on what does it sound like on a rotary? like a belt squeal like guy321 said? Would love to see several descriptions of detonation on a rotary.

thanks everyone

chris

Air Force RX8

Occasionally if you do not let the midgets out to stretch their legs they get angry and bang on the hood. I find that a good high pressure hose about once a week keeps them in their place. Seriously though, if you are going to use the cheap stuff at least throw a little octane booster in for good measure.

valpac

iTrader: (2)

Mazda recommends premium gas.