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Pelican Parts

2004 996 C4S vibration at idle

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

Discussion summary

YOUR RESEARCH2004 996 C4S vibration at idle

Reported or suspected cause

flywheel

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

It was the flywheel on a few of them, and an IMS retrofit to the LN IMS Solution on another handful of them that felt the issue was worthy of a couple thousand dollars.

2004 996 C4S vibration at idle
Frequently discussed work

Check motor mounts

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

Another thought is to check the motor mounts.

2004 996 C4S vibration at idle
Read full discussion summary

Leading evidence: 'flywheel' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'flywheel' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check motor mounts' (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.

Read captured replies

1 matching discussions · 2 captured posts examined · 0 partial discussions

Compare 4 other evidence results

worthy of a couple thousand dollars

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

It was the flywheel on a few of them, and an IMS retrofit to the LN IMS Solution on another handful of them that felt the issue was worthy of a couple thousand dollars.

2004 996 C4S vibration at idle

Clean injectors and throttle body

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

I've changed spark plugs, fuel filter, air filter, cleaned the injectors and throttle body.

2004 996 C4S vibration at idle

Replace spark plugs, fuel filter, air filter

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

I've changed spark plugs, fuel filter, air filter, cleaned the injectors and throttle body.

2004 996 C4S vibration at idle

Replace worn out transmission mount

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

Even replaced a worn out transmission mount.

2004 996 C4S vibration at idle
Frequently discussed actions (5)

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

Check motor mounts

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

Another thought is to check the motor mounts.

2004 996 C4S vibration at idle

Clean injectors and throttle body

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

I've changed spark plugs, fuel filter, air filter, cleaned the injectors and throttle body.

2004 996 C4S vibration at idle

Replace spark plugs, fuel filter, air filter

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

I've changed spark plugs, fuel filter, air filter, cleaned the injectors and throttle body.

2004 996 C4S vibration at idle

Replace worn out transmission mount

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

Even replaced a worn out transmission mount.

2004 996 C4S vibration at idle

Run car at any one time

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

Seems to worsen the longer I'm running the car at any one time.

2004 996 C4S vibration at idle
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.

flywheel

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

It was the flywheel on a few of them, and an IMS retrofit to the LN IMS Solution on another handful of them that felt the issue was worthy of a couple thousand dollars.

2004 996 C4S vibration at idle

worthy of a couple thousand dollars

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

It was the flywheel on a few of them, and an IMS retrofit to the LN IMS Solution on another handful of them that felt the issue was worthy of a couple thousand dollars.

2004 996 C4S vibration at idle
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.

2 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • Pelican Parts: 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: 20261026T161109Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1Original post

My 2004 911C4S has a rough idle that makes the car vibrate. Just a slight increase in RPM makes it smoothe out. I've changed spark plugs, fuel filter, air filter, cleaned the injectors and throttle body. Even replaced a worn out transmission mount. Runs great at speed but shakes when idling in stop and go traffic. Seems to worsen the longer I'm running the car at any one time. CEL is not on. Could this be an MAF problem even though I have no CEL alarm? What suggestions do you have? __________________ This post was auto-generated based upon a question asked on our tech article page here:

POST 2Original post

I've noticed that a few of the 2002-2004 996's have a lumpy idle. It was the flywheel on a few of them, and an IMS retrofit to the LN IMS Solution on another handful of them that felt the issue was worthy of a couple thousand dollars. Most of the cars however lived happily ever after with the vibration. Another thought is to check the motor mounts. - Casey

This is a source reference. Confirm exact model applicability in the original material.