4 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHDurametric
Leading reported evidence
Check cam position the other day
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
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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
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Performed · outcome unconfirmed · Original poster
Also I checked the cam position the other day and that seemed fine; no codes or warnings on that.
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
A failing or failed VarioCam solenoid or actuator can cause misfires as the DME attempts to adjust fueling to get the #2 O2 sensor readings it expects and the fueling gets too far out and the engine misfires as a result.
Leading evidence: 'Check cam position the other day' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust fueling' (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
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
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Suggestion
A failing or failed VarioCam solenoid or actuator can cause misfires as the DME attempts to adjust fueling to get the #2 O2 sensor readings it expects and the fueling gets too far out and the engine misfires as a result.
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 threshold indicators you have could possibly be camshaft deviation, this is related to worn chain rails inside the engine, or could be the solenoid used in the variable valve timing, these are well know to cause rough running on the 996 and might be worth replacing first as it's the easiest job and doesn't require any internal work.
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.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Adjust fueling
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
A failing or failed VarioCam solenoid or actuator can cause misfires as the DME attempts to adjust fueling to get the #2 O2 sensor readings it expects and the fueling gets too far out and the engine misfires as a result.
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 threshold indicators you have could possibly be camshaft deviation, this is related to worn chain rails inside the engine, or could be the solenoid used in the variable valve timing, these are well know to cause rough running on the 996 and might be worth replacing first as it's the easiest job and doesn't require any internal work.
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.
4 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: 20261026T122219Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Rough running threshold. I got up to 69.9 1/S squared (the lowest I logged looks to be 8.3 1/S squared)...what does that mean exactly?
Other data I pulled. Range 2 Cylinder 1-3 was at .98
Range 2 Cylinder 4-6 was at 1.02
Range 1 Cylinder 1-3 was 0.00
Range 1 Cylinder 4-6 was 0.02
My interpretation is cylinders 4-6 are not running correctly, or are correct and should read over 1. Codes I have all affect cylinder 3...
P0300
P0303
P1319
P1315
The threshold indicators you have could possibly be camshaft deviation, this is related to worn chain rails inside the engine, or could be the solenoid used in the variable valve timing, these are well know to cause rough running on the 996 and might be worth replacing first as it's the easiest job and doesn't require any internal work.
Noz thanks, do you happen to know the tolerance for the rough running threshold? Also I checked the cam position the other day and that seemed fine; no codes or warnings on that.
What exactly are you referring to, to replace that is easy. The solenoid or camshaft item, maybe the position sensor?
There is some detail in the factory manual about how misfires are determined. I can't recall the method off hand but vaguely for misfires to be actually classified as events worthy of logging error codes and turning on the CEL requires some time. This suggests that engine, various cylinders, could manifest misfire like behavior but as long as it remains of a short duration the behavior is not classified as misfires.
P1913 to P1919 error codes are emissions relevant misfire codes. These are I think the techs refer to as "rich" misfires. Other misfires are "mechanical" misfires.
Without knowing the car's history, for misfires at the top of the list has be plugs and coils. In one case I recall a bad MAF accounted for misfires on just one bank.
A failing or failed VarioCam solenoid or actuator can cause misfires as the DME attempts to adjust fueling to get the #2 O2 sensor readings it expects and the fueling gets too far out and the engine misfires as a result.
Without knowing what prompted you to take the readings you took other things can be going wrong.
This is a source reference. Confirm exact model applicability in the original material.
