13 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHRattling exhaust..
Reported or suspected cause
muffler off and shake it around
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause
Just pull the suspect muffler off and shake it around to see if it rattles.
Leading evidence: 'muffler off and shake it around' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'muffler off and shake it around' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check light' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
When you pop that muffler off to check for loose baffles.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
You shouldn't have to remove the exhaust tip if you aren't changing the exhaust.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
13 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T203514Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
New sound in my car's rear:
The right (passenger side) exhaust is rattling when hot at idle speeds only.. The noise is coming from the pot (is this the cat?) just behing the chrome tip. I tried to push it around to see if it's lose somewhere but the noise seems eminating from the inside of it.. Is it possible the cat material has cracked inside?
When i put the engine off and punch the pot, the same noise comes out of it for a split moment.. grrrat..graaat..!!
Suggestions?
Wael (69,000km)
Waz:
If the noise is coming from the muffler; there is a resonating chamber towards the top 1/3rd of the muffler. There could be some cracked weld slag that fell off of maybe the resonating piece it self has cracked and is rattling. I dissected one of my stock cans when installing the Gemballas; so I know what they look like.
Although, it could also be something with the cat. Just pull the suspect muffler off and shake it around to see if it rattles. There is three mounting bolts holding the muffler to the car. I believe they are 13mm; and a 19mm? bolt holds the exhaust clamp (muffler to the cat pipes). You shouldn't have to remove the exhaust tip if you aren't changing the exhaust.
Elias
Waz,
I have the same rattle on the same muffler (49656 miles). It looks like it might be a loose baffle on the right muffler for me or like mentioned before, the cat is approaching EOL!
I think we need new mufflers!
Better yet, time to upgrade the whole exhaust system...any suggestions on where to get RUF on Cent CAL?
TIA
-Freddy
Freddy, freddy... check my location! no way here i'll ship an exhaust over!!
Anyway, i am planning to open her up tomorrow and check out the noise. I am seriously thinking now to cancel the cats by either bypassing a similar diameter empty tube or by opening them up, emptying them, and rewelding them back.. what do you guys think?? Since they come AFTER the O2 sensor, will it affect in the electronics? will i get a check light? I know the noise will be a bit louder, for the better of it!
I dont understand the big triangular pot just behind the exhaust tip is the exhaust or the cat?? Are the cats those round wedged pipes in between the two exhaust tips??
Waz (with lots of questions)
996 C2 99
waz:
Another option... Since you do a lot of running with the Super bike guys... When you pop that muffler off to check for loose baffles. Pull the other one off and drive it like that! You'll finally be able to hear your car over the sport bike guys.
When I was messing with the stock system; I thought about just attaching a street elbow to the cat pipe and reweld the tips on to the street elbow. Basically it would be a design like Fabspeed's supercar exhaust?? No muffs!just straight pipes to the tips!
Good Luck, let me know how it turns out.
Elias
I have just dismantled the passenger side rattling exhaust.
1)To start with, the holding bolts were really rusted and there�s one that even was cracked. That is no problem I will change them to new ones.
2)The muffler is indeed rattling when we removed it and shake it. There�s like something inside that is lose. The only solution I have here is to open with Oxygen it and inspect it to stop/weld/fix/pack anything that is lose inside. I will re-weld it after having done it.
3)Each of the catalytic converters has a sensor before and after. I suppose they are to test exhausts pre and post catalysis. Do you suggest I should empty the honeycombs inside them? I can do that by again: cutting / emptying / re-welding. Many people here do that with their cars since our fuel is leaded and the cats eventually block as they say but I don�t know if this is really true.
MOST IMPORTANT, WILL IT AFFECT THE ELECTRONIC READING AND/OR CHECK ENGINE LIGHT ON THE DASH?
Wael
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Waz996:
<strong>3)Each of the catalytic converters has a sensor before and after. I suppose they are to test exhausts pre and post catalysis. Do you suggest I should empty the honeycombs inside them? I can do that by again: cutting / emptying / re-welding. Many people here do that with their cars since our fuel is leaded and the cats eventually block as they say but I don�t know if this is really true.
MOST IMPORTANT, WILL IT AFFECT THE ELECTRONIC READING AND/OR CHECK ENGINE LIGHT ON THE DASH?
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Yes, it certainly will give you a "check engine light".
So are you saying that you currently run the car on leaded fuel? Surely you have available somewhere unleaded at a slightly higher price??
S.
The rennlist picture-upload unfortunately doesnt work but i will post the guts-open mufler pics when the site is up again:
I have cut-open the exhaust muffler shell, surprisingly it seems to have two steel shells, about 1mm each..
-The exhaust manifolds breathe to the mufflers thru an inlet hole inside a first chamber.
-Then, gazes go to the second chamber thru a 1st inner pipe
- Two other inner pipes circulate the air from the 2nd inner chamber to a thrid chamber and then out to of the muffler to the cats.
Those short inner pipes are all tack-welded in-between the sealed chambers. The rattle was simply due to lose welds and i was able to weld the pipes all round again.
I closed the cover again, making sure to weld the thin sheets one by one again, and there it is: No more noises!!!
Waz
