Planet-9

987 Cayman S 3.4 misfire Cyl.2

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9 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH987 Cayman S 3.4 misfire Cyl.2

Leading reported evidence

Install when the engine was rebuilt ( 3 weeks ago)

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
New intake manifold gaskets that were installed when the engine was rebuilt ( 3 weeks ago) .
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Frequently discussed work

Inspect any plugs or connections

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’d closely inspect any plugs or connections.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Read full discussion summary

Leading evidence: 'Install when the engine was rebuilt ( 3 weeks ago)' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'fool's errand' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Inspect any plugs or connections' (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 · 9 captured posts examined · 1 partial discussions

Compare 4 other evidence results

fool's errand

Suggestion or failed attempt

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
I think swapping them with their neighbor is likely a fool's errand.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Inspect any plugs or connections

Suggestion or failed attempt

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’d closely inspect any plugs or connections.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Inspect intake gaskets and manifold

Suggestion or failed attempt

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'd pull the manifold and inspect the intake gaskets and manifold for issues/cracks/flaws before I rewired anything.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Replace engine wiring harness completely (or get new wiring done

Suggestion or failed attempt

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
thing to do is to change the engine wiring harness completely (or get new wiring done for ignition / injector on cyl.2).
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

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.

Inspect any plugs or connections

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’d closely inspect any plugs or connections.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Inspect intake gaskets and manifold

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'd pull the manifold and inspect the intake gaskets and manifold for issues/cracks/flaws before I rewired anything.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Install when the engine was rebuilt ( 3 weeks ago)

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
New intake manifold gaskets that were installed when the engine was rebuilt ( 3 weeks ago) .
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Replace engine wiring harness completely (or get new wiring done

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
thing to do is to change the engine wiring harness completely (or get new wiring done for ignition / injector on cyl.2).
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Smoke-test tbh

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 like the idea of a smoke test, TBH.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

Reported and suspected causes (1)

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

fool's errand

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
I think swapping them with their neighbor is likely a fool's errand.
Original post Read captured discussion
987 Cayman S 3.4 misfire Cyl.2

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.

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

Planet-9: 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: 20261027T011819Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1Original post

Hey guys, I have a 2006 Cayman S with the 3.4L with 70K miles. I have a random misfire on cylinder 2 for two years now. It only happens at idle from time to time. Since then, all the coils had been changed. The injectors and spark plugs too. I have a new rebuilt motor, but the problem was there before the rebuild. My mechanic is telling me that the next thing to do is to change the engine wiring harness completely (or get new wiring done for ignition / injector on cyl.2). I want to know your opinion about that. Here's the fault code on the Durametric if someone spot what's wrong. The code is P0302 and P0300 (checksum)

POST 2Original post

I'd pull the manifold and inspect the intake gaskets and manifold for issues/cracks/flaws before I rewired anything. Vacuum leak will cause a misfire. You might get lucky with a can of starter fluid and squirting it on and around the #2 runner/ manifold and listening for an RPM change. Then I'd move the coil...since it is easy and see if it moves. Then move the plug. Then move the injector. (in order of difficulty) Just because they are new doesn't mean they are any good.

POST 3Original post

It has new coils, new injectors installed this week. Still misfires, it's always the same Cyl.2 that has a misfire. New intake manifold gaskets that were installed when the engine was rebuilt ( 3 weeks ago) . Other than that, ... maybe a light crack on runner might be the issue too. Might try smoking the intake.

POST 4Original post

Compression all good? I’d still swap coil then plug. Easy to do and new stuff doesn’t always work. I’d closely inspect any plugs or connections. Make sure pad coil mounts to is spotless. That’s where they ground.

POST 5Original post

I would agree in theory but #2 misfired before this repair and after all new parts were installed. I think swapping them with their neighbor is likely a fool's errand. I'd certainly be making inquiries to whomever rebuilt it. Not sure on the wire harness either as how does said mechanic account for the intermittency and specific idle occurrence?

POST 6Original post

I'm not a fan of the wiring theory either but if the Cayman is the same "surgery via the fender liner" like the Spyder , and you're old, it's a long time in that mechanics seat and the heat shield origami puzzle piece game to avoid bending it (which I 100% refuse to do) can be a PIA.

POST 7Original post

When you say the engine was rebuilt 2 weeks ago - that begs the questions: Why? What was "rebuilt"?

POST 8Original post

I like the idea of a smoke test, TBH. Least expensive tests first are always a good idea, IMHO. I'd go down the wire harness route as a last resort...

POST 9Original post

Unrelated to your misfire issue.. how did you get the durametric software working on your mac? I have windows with the parallels software. But I never could get it to recognize.

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