Pin8, can you go to a local club meet so someone else can listen?

It mat be the marbles in a can sound which is air in the radiator.

Also, you have to be careful with that Carb cleaner. Your cat could be bad now.

 

i am running catless..i'll be at seven stock saturday

 

Track me down, I want to hear that knocking sound at idle.

 

what do u mean air in the radiator? And how is that a problem"?

 

Air in the water cooling sytem leads to hot spots and less cooling.

Most of the marble in the can sounds are air in the system.

Bleed it..........

 

I think i have marbles in a can? If i got marbles in a can... does it do it at all times ...?? I only get a rattling noise at WOT+above5k.... while in drive.... NEVER in PARK..

 

There are two sounds and two different problems we have here. The one thats a liquid being restricted in a hose(similar to a water hose being squeezed at high pressure). Is this post problem.


https://www.rx8club.com/rx-8-discussion-3/please-help-potential-new-owner-question-miac-181950/

If you have "MIAC"(Marbles In A Can) sound it is more of a Kegger getting hit by a lead hammer. This is preignition in a rotary engine. It is very damaging and needs immediate attention. It could be fixed by changing to a higher octane fuel or several other things could be causing this.

 

^no my does not sound anything like that..... mine only does it.... in drive above 4500 rpm at WOT....a rattling sound... imma go get some video right now...

 

ah..does lacking of AC cooling have to do with this? my AC is only cool while the car is moving but when i come to a stop, it feels like a fan..i will track you down though razz..

 

volcom is yours the same as in the video?

 

no, its like the video i posted..only at idle

 

zumn, is your car AT? mine is AT with 69k miles (2nd engine)

 

Ok VOLCOM.... i got video of mine... it wasnt really doing it right now.... i just think its something loose on/near the exhaust.... or the heat shield... but it doesnt do it at idle.... ill put vids up.... im uploading to youtube right now...

 

AT 4 port 70k mi, 1st engine... runs smooth just makes this little noise sometimes.... rarely... i just think its something loose... imma upload vids right now...

 

Volcom videos are uploading..... now i just need to edit them...

 

VOLCOM- listen closely .... turn up the volume a bit.... from 4500 to 5500 rpm it makes a rattling noise... but outside of those RPMS everything is perfect... is this how yours sounds? The first video is during idle.... and does no noise whatsoever...

PERFECT AT IDLE...
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Rough rattling from 4500 to 5500, everywhere else....perfect...

[EMBED]6SnbtCywzH0[/EMBED]

 

i couldn't really hear the noise..lol

 

well you are coming to the caravan for SS right? if so.... then you;ll hear it then....

 

if u were to make avideo like i did can you hear it??:?

 

i'll check it out on saturday..are you going to cerritos at 5 am?

 

IM on the list aint I? LOL@@ yeah ill be there...

 

So here is a update.

The same issue I had happened again on a long trip even with the fuel additive (not as bad but it's still happening) I brought it to Wayne Mazda in NJ since people here suggested they are good and Kevin works there. Kevin wasn't there that day, but they had a senior Tech work on it for 2 or three hours did a compression test checked the CAT and whatever else they did and found nothing. (The service desk guy told me that they had a Mazda engineer look at it since he was there that day.) They didn't charge me a diag fee which I'm surprised at, but they seemed like they tried.

The noised that I have after long trips is not the knocking. It's accompanied by lack of power. Would air in the coolant line cause lack of power? I'll try to bleed the system since maybe what I'm hearing is a extension of the fluttering that I hear sometimes ( that may be the coolant system.) The sound sound's like popping coming from inside the car or someone hitting a hollow metal object with a hammer. It only happens sometime so I can't just go to a meet and have people check it out since it may not happen then.

 

Did you read mesg #32 above this one? It sounds like pre-ignition...what octane fuel are you using? Are you pre-mixing?

 

Sorry I did but, somehow the first part only registered. I think that now we are pretty sure that it's pre-ignition.
I don't pre-mix. Do you think pre-mixing will help? I usually use 93 octane and sometimes 91.
What are the other things that may cause pre-ignition?

 

I had MIAC and Mazda did a de-carbon cleaning and it went away for a few thousand miles and started again. I did the TB by-pass and went to prem-fuel only and started pre-mixing no problems since.