Rx8 rattle under car?
 

So its been about a month since i got my car back from dealer with reman engine and its been running flawless but today I heard a weird noise coming from under the car. Anyone car to listen? Also there's no CEL's or random issues that I know of; 04 6pd, 72k, plugs, coils, wires changed at 60k just to mention. The noise came on after a 30 min drive its the first time i heard it.

Well here's the vid and thanks for watching.

http://www.youtube.com/watch?v=mV1PqoxAzfY

Check around the cat and exhaust.

sounds like a leak in the exhaust or the cat material is rattling inside the exhaust.
also does this sound go away when you push in the clutch?

Ill have to check tomorrow. I hope its not my cat i had it replaced 10k ago under warranty. I hope the dealer doesn't have to keep my car long. It was there a month and half for engine replace i don't want to give her back lol. If its exhaust leak does that mean i can finally just get my borla and say screw stock?

My 8 has the same noise.
But mine also has blown transmission that's where i though noise was coming from.

However my cat is also clogged ( won't rev past 6 k )
so it could be from that as well will no for sure once car gets back from trans rebuild.

I hope i don't have a blown transmission :(. Is it ok for me to drive with this noise for a little?

You would no lol.

My 8 would not drive at all. and will leak 4 quarts of atf within 3 minutes.
it is COMPLETELY BLOWN Literally lmao.

im sure your trans is fine.
might be the cat i think that's what it is on mine now to since i saw your video and your trans is fine.

Thanks for your input!

Update:

Went out on a little drive. Noise does go away when i push clutch. What does that mean? Also it comes and goes i don't hear it all the time....

well, a normal transmission would make some noise in neutral when idling but not this loud. I suspect something on the clutch might not be installed correctly or failing.

Bummer. Could be a leak in exhaust or cat like you suggested earlier as my tranny seems to be ok i guess. My last question and ill let the dealer handle from here. Is it harmful to my car if i drive it with this for a bit? I don't want to ruin anything and make my problem worse?

i don't no much, but,


does your car rev freely? if so id say it's fine to drive.
i was told by another member that since my 8 only revs up to 6k that i should not drive at all
due to major increase in back-pressure.

if it is your cat that's making the noise it's most likely in early stages of failure if your car rev's freely.

Def go get it checked out if you got warranty

no your transmission is fine. its the clutch. could be a noisy bearing. thats why I want you make sure if its clutch related or not.

I changed my clutch out around 50k, (72k now) exedy stage 1, maybe when the dealer put my engine in they jacked up something. My guess is a loose bracket on the exhaust but im going to wait it out till the beginning of the month and get the racing beat exhaust to match my RB revi intake. If i figure out exactly where that noise is coming from ill post so others with similar noises can identify. Thank you guys for all your help. Ill roll until i get a CEL; when I do ill just take to dealer (im still under warranty till april 2012 or 86k). Thank you again!

I have the exact same sound coming from my car however it stops completely once its warmed up :S I'm guessing its something loose

Check the heat shield under the catalytic converter. I had a sound just like that and thought is was the tranny but it turned out the heat shield was corroded and part of it came loose and was rattling. If I recall right, there is even a tsb for this.

Will definitely look into that bud! Pardon my ignorance but if my tranny was going bad im assuming it would be pretty obvious right? What would a bad tranny sound like?.

Nevermind i searched from my phones browser and im ready through sticky on trannys right now!

If the sound goes away once the car is warm it is VERY LIKELY TO BE THE HEAT SHIELD AROUND THE CAT. (not the cat itself). After a few years, they tend to rust and then break.
Exhaust warms up --> heat makes the loose parts expand --> contact better and stop rattling.

To test this, get a hammer and go under and hit the heat shield. if it makes anything except a solid clunk then thats probably your issue.

if this IS this issue, fix it by getting some long (12-18 inches) section of hose clamp, and wrap it around the whole thing tightly. Should hold it off for another 30k miles...

:sadwavey: If he pushes in the clutch, the noise goes away.

Throw out bearing.

Oh...missed that. Good call :-)

welp my heat shield is hangin by a thread! I'm gonna weld it when I switch out the motor mounts this weekend! it's the worst... huge vibration and shit rattling! cant wait to just hear her purr again

I have a similar problem when warming up the car. But it has only happened 3 times over the past 2 months and sound is gone after warm up.

Brought it down to workshop but since the sound wasnt there they couldnt diagnose it other than say it might be clutch bearings being worn out. Told me to depress the clutch to see if the sound disappears but unfortunately it hasnt.

Interesting, now at least know it may be the heat shield. What if I dont get it fixed? will it be dangerous? thanks

I have had a little chattering sound since I bought my car at 18k miles when I release the clutch, but nothing that loud. Similar in sound though.

Hey guys sorry if im jumping on this but im having a little bit of the same problem I recently hit a bad bump in the road. :banghead: and it dented my cat up and scraped it but when im accelerating and get the rpms up to about 3.5k-4k it makes a rattle sound coming right below my shifter about where the cat is if im not mistaking. but its like a airy dragging like sound. it gets louder and mor frequent when im driving in the morning when its still a little cold out but once its hot out side i barley hear it especially when i tried to show my friend the problem. does anybody know anything on these symptoms. Mazda told me its bad to drive my car with these symptoms and im scared. :uhh: