3 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHresonant whistle
Leading reported evidence
Replace (roller bearing), new aos
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
Newer transmission rebuild (CMS) with G50 LSD, IMS replaced (roller bearing), new AOS.
Leading evidence: 'Replace (roller bearing), new aos' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check case vacuum see if you have a vacuum leak' (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.
Suggestion
I'd check your case vacuum see if you have a vacuum leak...
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 · Original poster
Anyone think this could be the AOS (again, just replaced)?
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 · Original poster
Owner has generic oil in the case, kind of curious if changing oil would impact it?
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.
3 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.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
I've owned it a couple days, still getting used to it but it's a lot of fun.
New-to-me 2000 C2 cabrio with 104k. Newer transmission rebuild (CMS) with G50 LSD, IMS replaced (roller bearing), new AOS. Trans and IMS have about 3K on them. I've owned it a couple days, still getting used to it but it's a lot of fun.
Vehicle has a resonant "whistle" which sounds like an overtone of what I think is normal gear whine from the transmission. It sounds like someone blowing over the top of a bottle, but higher pitch. I don't think the whine itself is an issue - normal for a 996 esp with a new box - but the "whistle" is interesting. It is only present between 2400 and 2600rpm, fades in and out at lower and higher revs. Prominent in parking lots as that's kind of where the revs sit at 10mph in first, can't really hear it at all on the highway.
Video below is from under the car directly below the trans, so the gear whine is very loud - important to note the whistle is audible from outside the car but the gear whine is not this loud in the car. You can hear the whistle as the revs hit 2400.
https://youtube.com/shorts/yfwYMXV_i...eL_zp1e7Y5-tft
I haven't pulled the belt but it really doesn't sound like bearing noise, which I would expect to escalate in volume with higher revs. Stock airbox. Newer 200 cell cats. Noise is same with clutch in/out, in neutral, or in gear.
I reached out to CMS and the IMS seller, both say it's not transmission or IMS.
Owner has generic oil in the case, kind of curious if changing oil would impact it? Anyone think this could be the AOS (again, just replaced)?
Nothing else is wrong with the car, just the "whistle" which IDK maybe is normal-ish. First 996, car definitely has character.
There are several places like the oil filler tube that create odd sounds if they crack.. I'd check your case vacuum see if you have a vacuum leak...
My 6 speed has a light Getrag whine in 5th and 6th.. Every getrag box I've owned had it to some extent. (Ford pickups, BMW, etc.. )
Thanks for those suggestions. You must be a fellow Portlander - I stopped by A&P today and had two of the techs plus the owner Alan listen to it. Opinion is, yes it is on the noisier side but not worrisome, and probably just normal for the mileage. Possibly the tensioner pads for the cam chains are nearing EOL. The advice from Alan was to not even worry about it and to keep driving it until there's another reason to drop the engine. Techs were more concerned about a partial misfire which I hadn't even picked up on.
This is a source reference. Confirm exact model applicability in the original material.
