28 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHMy 911 has a Cylinder Misfire
Leading reported evidence
Replace trans fluid and filter
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed · Original poster
Note: While my car was in the shop in January they changed the trans fluid and filter.
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Suggestion
However, if these plugs and coils are super old or in poor condition, go ahead and �check the box,� but there�s no replacement for good, old, troubleshooting either.
Leading evidence: 'Replace trans fluid and filter' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check box,�' (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 performed work without a confirmed outcome
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Performed · outcome unconfirmed
When I updated to the 997 coil packs I used flanged button head bolts (M6 x 40mm) to avoid dealing with spacers on the heat shields.
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
However, if these plugs and coils are super old or in poor condition, go ahead and �check the box,� but there�s no replacement for good, old, troubleshooting either.
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.
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Suggestion
PT3 suggestion checking tire pressure is very good, diffidently do that 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 · Original poster
OK, so after replacing #1 plug and coil the car ran great with no engine miss.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check box,�
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
However, if these plugs and coils are super old or in poor condition, go ahead and �check the box,� but there�s no replacement for good, old, troubleshooting either.
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
Probably should change all 6 plugs and coils but at this time I'm only going to change coil and plug on Cylinder 1 and hopefully the code wont reappear ...
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
Probably should change all 6 plugs and coils but at this time I'm only going to change coil and plug on Cylinder 1 and hopefully the code wont reappear ...
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.
28 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.
2 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
It�s entirely possible that changing plugs and/or coils results in no change to the code (doesn�t fix the issue).
I have a 99' 911 and yesterday when I started the car I felt an engine misfire.
Connected my OBDII meter and code
P0301
appeared Cyl 1 Misfire
Does that usually indicate a Spark Plug or Coil issue?
Thanks
Mileage=106,000
Bought car recently and I have no maint records.
Probably should change all 6 plugs and coils but at this time I'm only going to change coil and plug on Cylinder 1 and hopefully the code wont reappear ...
Process of elimination, I like it ...
I'm wondering how difficult is it to change cylinder 1 plug and coil.
I think cylinder 1 is on the drivers side, cylinder facing the rear bumper ...
3 4
2 5
1 6
You could very well have a leaking coolant expansion tank also which is above it. Mine had cracked coil packs, then combine that with a leaking coolant expansion tank that drips, you get the misfire.
Only get the Porsche replacement tank, unless of course, you want to do it more than once.
It�s entirely possible that changing plugs and/or coils results in no change to the code (doesn�t fix the issue). However, if these plugs and coils are super old or in poor condition, go ahead and �check the box,� but there�s no replacement for good, old, troubleshooting either.
Yes, it is a bit finicky getting at #1 (and #6) but not impossible with a good tool set. I just upgraded mine to the 997 style and it took about an hour to do all 6 of them.
3 4
2 5
1 6
This is my 1st Porsche but most other sports cars I've owned it was easier to get to the plugs facing you Vs the ones facing the firewall but I'll soon find out first hand ...
Did you not see my post? And, no plugs face the firewall, but you will have to remove the heat shields and work your way around the exhaust system. The old coil packs with the inset bolt heads are difficult to remove. But the upgraded 997 coil packs are easy to install with a 10mm wrench. Good luck...
You can get to the coils & plugs via the rear wheel well. 2 & 3 are easily accessible, 1 is somewhat more complicated. You'll probably need a swivel extension to get the plug out.
Be careful if you opt for 997 coils, you'll need a spacer for the heat shield, as well as different bolts. Mine had a torx E head, so you'll need that socket too.
When I updated to the 997 coil packs I used flanged button head bolts (M6 x 40mm) to avoid dealing with spacers on the heat shields. They were similar to this:
Amazon
Amazon
It took me a couple of hours to replace cylinder 1 plug and coil (mainly because it's tough to get to it) location, location ..
When I removed the old coil a considerable amount of oil poured out of the plug hole. I removed the oil before installing the new plug and coil.
My question is, is there a broken seal causing the oil leak?
Given it's location I bet it's near impossible to replace it ...
That would be a spark plug tube. It has 2 seals on it and its easily removed. For that tight location i would get an expanding plug that r usually found in marine applications to seal the haul drain port. Basically insert the plug, tighten the handle and pull. There r several other methods out there if u search. Maybe the oil was just screwing up the spark?
As @
De Jeeper
mentioned, you have the 5-chain engine that has the Variocam camshaft adjuster and spark plug tubes. The Variocam solenoid seal and spark plugs tubes should be replaced while you're swapping out the plugs and coil packs IMHO.
Watch this guys video. He's replacing the tubes on a 5-chain M96 that has the same setup as you.
You Tube
You Tube
OK, so after replacing #1 plug and coil the car ran great with no engine miss.
I don't think they are related but 2 days later I tried to start my car and the starter turns over perfectly but no spark.
Suggestions ...
Also, while in Drive the auto trans shifts perfectly, except when it should shift to 5th gear it doesn't.
If I select Manual it will shift to 5th just fine. Note: While my car was in the shop in January they changed the trans fluid and filter.
Suggestions ...
I bought a CT6 Caddy for long road trips with my wife (for some reason she doesn't like long road trips in my Porsche) so I've been getting familiar with all of the Caddy do dads, I haven't drove my Porsche for a couple of months but in the mean time I've been starting it and letting it run for 15 minutes just to keep it lubricated.
Now I'm driving the Porsche again and that's when I found the engine miss issue. And now I have something going on with the transmission. Moral of this story, Don't set-up your Porsche for any length of time :-)
Check the tyre pressures, also the tyre sizes and the tread wear/tread depth...If the tyre circumferences are not equal ( especially the front tyres) the tyres will spin at different speeds and via the wheel speed sensors, and the trans will assume the car is in a turn, the trans will not automatically upshift to 5th gear when in a turn...
There is normal procedure for storing a car correctly to prevent any damage/wear. It has been discussed here many times ,do a search if ya want...
PT3 suggestion checking tire pressure is very good, diffidently do that first...
jmo
Update:
I tried to crank it today and it worked great.
Even though I didn't get any idiot lights I connected my OBDII reader and it responded with (Mfg code, enter vehicle Mfg) I entered
Porsche
and it indicated
P1600 Voltage Supply
.
When I started using my car again I noticed cranking didn't sound full strength so I charged the battery over night.
Other than the trans issue everything is OK.
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