6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHirregular idle
Leading reported evidence
Check engine!" warning
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
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Suggestion
The only thing that doesn't ring true in your case is that you usually get the "Check Engine!" warning on the on-board computer when one of the coils is playing up....?
Leading evidence: 'Check engine!" warning' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check engine!" warning' (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
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Suggestion
If it is one of the coil packs then you'll be best to replace all six of them as the others will probably be the same age and it can be false economy to just replace the broken one.
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.
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Suggestion
I've been told that a couple of mine are cracking (the bodies of them are made from moulded plastic) and will need replacing soon but I'll wait until the engine starts to show symptoms first.
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.
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Suggestion
You're effectively running on 5 instead of six cylinders.
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.
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Suggestion
If this is the case it would have the same effect as pulling the HT lead off one of the spark plugs whilst the engine is running on any "normal" car.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check engine!" warning
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
The only thing that doesn't ring true in your case is that you usually get the "Check Engine!" warning on the on-board computer when one of the coils is playing up....?
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
If it is one of the coil packs then you'll be best to replace all six of them as the others will probably be the same age and it can be false economy to just replace the broken one.
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've been told that a couple of mine are cracking (the bodies of them are made from moulded plastic) and will need replacing soon but I'll wait until the engine starts to show symptoms first.
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.
6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Porsche Club GB: 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: 20261026T120458Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Hi All,
I have now had 1999 996 C4 Cab for 3 months after filling up last week the car has started to idle roughly, you can feel the car rocking from side to side when stationary. Reminds me of an old 1969 Beetle I had years ago.
Does this sound like rubbish petrol as it was fine before I filled up.
Sorry if this is a dumb question but waited 22 years for my 911 and just worried that it's about to go wrong.
Hi Matt and welcome.
It sounds like one (or more) of the coil packs that sit on top of each of you six spark plugs is either on its way out or broken. If this is the case it would have the same effect as pulling the HT lead off one of the spark plugs whilst the engine is running on any "normal" car. You're effectively running on 5 instead of six cylinders.
The coil packs on these cars are very exposed to the elements as they're very near the ground and tend to get a lot of abuse from rain, dirt and general oomska off the road. I've been told that a couple of mine are cracking (the bodies of them are made from moulded plastic) and will need replacing soon but I'll wait until the engine starts to show symptoms first.
The only thing that doesn't ring true in your case is that you usually get the "Check Engine!" warning on the on-board computer when one of the coils is playing up....? Has this appeared? The best way to check it all out is to take the car to your local independent Porsche specialist (not an OPC - they'll charge you loads for the privilege of plugging their tester into your 'dash) and get them to have a look. If it is one of the coil packs then you'll be best to replace all six of them as the others will probably be the same age and it can be false economy to just replace the broken one. From memory I think it'll cost around £300 for all six coil packs from somewhere like Euro Car Parts - have a look on their website.
Hope this helps.
Adrian.
Hi,
I was looking up coilpacks on ECP recently too. They have Beru and Bosch at 30 and 23 each respectively (excl vat).
Has anyone any opinion on which is the best to go for?
What is the price from Porsche?
Had all six done last week at OPC Newcastle - £34.98 each + VAT (may include discount for membership of PCGB / 1998 car) ..and 1 hour labour to fit [
]
That's the list price for them.
Mike - Porsche fit Beru or Bosch, depending on availability. I believe Bosch were in short supply recently, and they would be my preference, but I have no evidence they are any better than Beru.
Hi Adrian,
Many thanks for your help. I phoned a local Porsche specialist and he asked about the engine light too. It has not come on, so he suggested a run out in the car. Which I did early on the Bank holiday Monday. After a few miles it ran fine and now has no problems?
Maybe it was duff Murco fuel?? The first and now the last time I use that service station.
There is a club event in Tadworth on Monday according to 911 world so I will take it there.
Many thanks
Matt
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