"Marbles in a can" sound

[jaii13]

I don't know what to call this sound, but the term, I think, describes it best. Please click on the link, the description of the occurrence of the sound is perfect.

http://www.rx8club.com/showthread.php?t=93836

I wonder if you RE owners get this as well? Or is this problem only happen to RX-8s?

Interesting post from that link: http://www.rx8club.com/showpost.php?p=1436728&postcount=12

And that brought me back to this link by diablo: http://www.zerotohundred.com/newforums/showthread.php?t=73236

I'm still not sure what's the cause and the fix for this. My car runs fine, in fact the sound has been there for quite a while, I never paid too much attention on it till I stumbled on the thread at rx8club.com.

So... anyone?

 

[Lennon]

The Marble sound might be crack 'beehives' in your cat....... This problem is very famous among 8....

 

[phat7]

sounds to me like pinging. what are your mods? usually a less restrictive intake can cause lean at high rpm's on stock ecus.

 

[jaii13]

sounds to me like pinging. what are your mods? usually a less restrictive intake can cause lean at high rpm's on stock ecus.

I only changed my exhaust, still using the stock air filter box.

 

[phat7]

yes jai, the exhaust is less restrictive. you see the fd guys know the common 3mod rule. if you exceed you then run the chance of damaging the engine.

 

[jaii13]

Oh snap.

So does that mean getting an open pod air filter will get rid of pinging?

 

[Alchemis]

hmmm not sure about if it's pinging...

but these sound can range from loose bolt around the exhaust DP/MP to anything that's loose...

engineering term called it as imbalance rotation... but less likely...

maybe it's an exhaust related issue.... i think i heard before someone's 8 have strange sound after CAT bypass.....

just a guess...

if it's a pinging... air filter will make it worse.... u'll probably kill your engine. if the theory of 7 and 8 are same... then the next thing u need to do is get yourself a ECU that allow more petrol :P then only ur intake...

good luck

 

[- D i a b l o -]

weird,I dont experience anything like you mentioned.

Oh ya,the followthru for my 2T project is going fine.No problems so far.Its still silky smooth.

I reduced the amount and the frequency of oil added too.The "yucky" smell is faint now and almost nonexistant.

thumbs up for the project

 

[jaii13]

hmmm not sure about if it's pinging...

but these sound can range from loose bolt around the exhaust DP/MP to anything that's loose...

engineering term called it as imbalance rotation... but less likely...

maybe it's an exhaust related issue.... i think i heard before someone's 8 have strange sound after CAT bypass.....

just a guess...

if it's a pinging... air filter will make it worse.... u'll probably kill your engine. if the theory of 7 and 8 are same... then the next thing u need to do is get yourself a ECU that allow more petrol :P then only ur intake...

good luck

My conversations with friends says that it's most likely pinging. But, my friends do not own RE cars. I don't know how much difference there is between a conventional engine and the rotary in terms of this issue.

Those of you with experience and knowledge on this, please chip in. Really appreciate it guys.

 

[DRFT_240sx]

rotary doesn't tolerate pinging very well compared to their piston counterparts. =)