7 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCarbon Buildup in Exhaust
Leading reported evidence
Clean exhaust tip
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 · Original poster
They changed the injector and cleaned the exhaust tip.
Leading evidence: 'Clean exhaust tip' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Clean exhaust tip' (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
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 · Original poster
They changed the injector and cleaned the exhaust tip.
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.
Suggestion · Original poster
I've not pulled the plugs to determine if they appear fouled and the car does not feel as if it is running on fouled plugs.
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.
7 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.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Drove it for a few thousand more miles and no difference.
My 03 996 began showing excessive carbon deposits in, on and around the exhaust tips and on the bumper at about 6k miles. 1st warranty service attempt indicated it was a PVC valve that was out of spec. Drove it for a few thousand more miles and no difference. 2nd warranty service attempt they stated it appeared to be happening after the engine was turned off as they could not find any abnormal data on the OBC readouts. They dropped the exhaust on the right bank (left exhaust tip) and noted excessive carbon on one of the exhaust ports. They supposedly found that the injector was leaking gasoline into the combustion chamber so that on start up, excess carbon was resulting leading to the problem. They changed the injector and cleaned the exhaust tip. After a few more thousand miles now, it appears the carbon problem continues. Curious if anyone else has seen this problem or knows of a resolution?
Can you post pics to show how bad is your carbon build up? Is there any exhaust leak and which tip do you have? Do you see smoke upon startup or during hard driving? Your plugs may be fouled somehow due to the leaky injectors.
No smoke on startup or hard driving. I've not pulled the plugs to determine if they appear fouled and the car does not feel as if it is running on fouled plugs. The mechanic indicated that the voltage from the distributor was so high, plug fouling would only happen under extreme conditions such as valve or ring damage. I thought it could be because the majority of my driving is inner city (sorry to say) but why the carbon would only appear on one side is the mystery.
Appreciate any other thoughts or if anyone has had similar experience and resolution.
What does your scanner show for fuel trim and secondary O2 sensor readings at low rpm? Don't have a scanner...get one if you want to properly diagnois any new car. Could simply be a lazy primary o2 sensor on that bank making you run rich at low speed.
If you do a search here, you will find several suggestions. The one I have is a PC based program that is no longer available. Make sure it shows you at least the following live readings:
Engine Load
Engine Temp
Engine Compartment Temp
Timing
Fuel Trims
O2 Sensors
MAF
