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Vibration at approx 4000 rpm

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7 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHVibration at approx 4000 rpm

Reported or suspected cause

likely a bad bad thing

Reported cause

No successful repair reported for this finding.

1
Identified cause
0
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 report identifying 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.

Reported cause

Vibrations does not fix itself, so running it, without a goal to fix the issue is likely a bad bad thing.

Original post Read captured discussion
Vibration at approx 4000 rpm
Frequently discussed work

Recommend not

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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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 would recommend NOT running the engine at power till you sort it, you can break a crank fairly easily.

Original post Read captured discussion
Vibration at approx 4000 rpm
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Leading evidence: 'likely a bad bad thing' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'likely a bad bad thing' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Recommend not' (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.

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1 matching discussions · 7 captured posts examined · 0 partial discussions

Compare 3 other evidence results

Replace motor and transmission mounts

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

I recently replaced the motor and transmission mounts, that didn't really improve the situation.

Original post Read captured discussion
Vibration at approx 4000 rpm

thing

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

Vibrations does not fix itself, so running it, without a goal to fix the issue is likely a bad bad thing.

Original post Read captured discussion
Vibration at approx 4000 rpm

Recommend not

Suggestion or failed attempt

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 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 would recommend NOT running the engine at power till you sort it, you can break a crank fairly easily.

Original post Read captured discussion
Vibration at approx 4000 rpm
Frequently discussed actions (2)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Recommend not

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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 would recommend NOT running the engine at power till you sort it, you can break a crank fairly easily.

Original post Read captured discussion
Vibration at approx 4000 rpm

Replace motor and transmission mounts

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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

I recently replaced the motor and transmission mounts, that didn't really improve the situation.

Original post Read captured discussion
Vibration at approx 4000 rpm
Reported and suspected causes (2)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

likely a bad bad thing

No successful repair reported for this finding.

1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Discussions that report identifying 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.

Reported cause

Vibrations does not fix itself, so running it, without a goal to fix the issue is likely a bad bad thing.

Original post Read captured discussion
Vibration at approx 4000 rpm

thing

No successful repair reported for this finding.

0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
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

Vibrations does not fix itself, so running it, without a goal to fix the issue is likely a bad bad thing.

Original post Read captured discussion
Vibration at approx 4000 rpm
Coverage and how to read this overview

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.

7 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: 20261026T165820Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I have a 996.1 3.4 (6-speed manual), and I have been experiencing vibration in the 4000 rpm range. I recently replaced the motor and transmission mounts, that didn't really improve the situation. Anything else I should be looking at? I believe the car is on it's original clutch and flywheel at 130k miles

POST 3 / ORIGINAL POSTEROriginal post

I should mention that the sound is pretty terrible at around 4k RPM. Any further ideas on what I should look at?

POST 4Original post

Quotes source post: 18747161

This should be your next step. The dmf come apart and will cause your issue. Only other guess would be to look at your cam deviations and your actual deviation to verify the variocams r operating correctly and r within their limits.

POST 5Original post

Quotes source post: 18814651

What are the limits for actual deviation? Do you measure with engine running or while driving?

POST 6 / ORIGINAL POSTEROriginal post

Thanks for the feedback. The engine is so smooth at 2000 rpm, but the vibration (and noise) starts to grow at around 3500 rpm, and by the time I get to 4000 rpm it's time to change up to avoid the noise. I'm missing out on hearing the glorious howl of the flat-6. Hoping it's just the flywheel and / or cam deviation

POST 7Original post

Sounds like the dual mass flywheel may be de-laminating to me... Or you've lost a piece of the clutch lining and your out of balance. When I pulled my 2003 engine, the clutch was in great shape with almost 60K on it. The rubber in the dual mass flywheel was tired and the ring was moving out of spec. The dual mass is not just for clutch, its also a harmonic balancer for the engine, I would recommend NOT running the engine at power till you sort it, you can break a crank fairly easily. Vibrations does not fix itself, so running it, without a goal to fix the issue is likely a bad bad thing.

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