let me preface this by saying i searched for this issue and found nothing. This morning i got in my car, turned it on, then went to scrape ice off the outside. As i was scraping all of a sudden from the middle underneath of the car I heard what sounded like 2 marbles in a soup can being shaken moderately (the idle continued to sound normal and healthy). I finished scraping ice in the next 3-5 minutes and the sound had immediately quieted to a muffled version of the same sound. I got in the car and i could not hear it. The car revved perfectly fine and felt smooth and normal. No CELs were popped and when i arrived at my destination the sound was gone.

Bad Cat Converter?
Bad motor mounts?
dead apex seals?
any thoughts?

 

Maybe bad heat shield around the cat? The tack welds can break. The sheet metal might be making that sound.

 

could have been a cold cold cat. if it was motor mounds the car would shake during driving, and if it was an apex seal you'd know. other than the sound, is the performance still the same? if so it just could be the pre-cursor to a future cat problem.

 

you mean the precursor to an upgrade to a hi-flow cat

yeah it drove the same and when i came home from work it didnt make the sound.

 

This could be it. That is what happened on my toyota.

 

I think i may have had nearly the same thing happen. I've read countless threads on marbles in a blender, so have always been curious if I 'had' it, but never have had an issue at all.

But this morning, it was cold, i started up the car, let it sit for maybe 2 minutes, before pulling out. Within like a minute, I was probably going about 25, in 2nd (under 4k rpm cause car still cold), when i heard the marbles....came from the "right side of the car" like most people say and unmistakable. As soon as I shifted to 3rd (I always keep revs low until the car is properly warmed), the sound vanished.

Just as you described though, after it went away, I can hear a very very very quiet version of the same thing normally. But it comes and goes. Its so quiet that its not "an issue". But I can hear it. I have no recognizable power loss in any rpm range or anythign like that. Problem never came back in my 10 mile trip to work. Should I be concerned?


for the recrod (I always keep revs under 4k before it hits operating temp, then wait an extra 5 minutes after that before really opening it up). I have a 6sp 2004 with 32K miles, have done the recall and rev it up at least once a day to redline.

 

i had the same prob for 2-3 weeks i got so mad i put the car on a lift and got a fried to rev it to 3-4k on and off to make the rattle. the diff has an arm connected to it, and one of the bolts was lose :S how i dunno

 

You mean the Power Plant Frame??

 

Hello all,

My Rx-8 has just turned over 2,000km and only a month old.
I followed the break-in recommendations of keeping the revs below 4000 for the first 2000kms and now that I have babied her, I wanted to let it loose on the hwy on the weekend.
At about 7000 in 2nd gear I heard the noise, but as soon as i shifted to 3rd it disappeared until the revs climbed to around 7000 again.
I have finally heard the sound that you are all describing and I think it might be an input shaft bearing noise in the manual transmission, because when the transmission is in Neutral and I tried to duplicate the noise by revving to 7000 - 8000rpm, no noise was heard.
I think the only way to totally Isolate this noise it to have the car on a dyno and have someone carefully listen to where the noise is coming from as the revs climb with the car in gear. Who ever tries this needs to be super careful to avoid coming into contact or getting too close to spinning driveshafts or wheels, but would be nice to put this issue to bed once and for all.