15 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHnon-linear acceleration on my C5S
Leading reported evidence
Check google
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
Checked the google for a minute, then stepped out of the car to investigate.
Leading evidence: 'Check google' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check google' (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.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
Of course, I don't have all of the values needed to check these things but I'm trusting that the durametric will tell me if something is out of spec.
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.
15 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: 20261027T154520Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
As a long time AC guy I really wanted a more modern car (like TheMystro). So last year I pulled the trigger and sold my 89 C4 and bought an 04 C4S. Awesome car and although it had the IMS failure prior to me buying it, it has a new engine (about 6k miles with the LN Engineering bearing kit) and it has been problem free (I've only put 4k on the clock). What I do note, now that I am able to drive it more, is that the acceleration is not linear. When you apply the gas, at about 3-3.5k RPM it feels like there is a short boost of acceleration. It is really noticeable and while the car runs flawlessly, idles very smooth and has no registered fault codes, it bugs me that it has this non-linear feel to the gas pedal. Previous owner did have some ECU reflash done and I suspect that. Other things I have considered are the gas pedal electronics or the TPS or, possibly the variocam system?
I have a durametric and I can read out the TPS and other values but nothing appears to be out of spec. Of course, I don't have all of the values needed to check these things but I'm trusting that the durametric will tell me if something is out of spec.
Any hints or diagnostics I can do to sort out this issue? I'm planning an epic road trip and I don't want to find out I have a problem 2k miles into a 5k mile trip.
TIA
The boost is normal as your car has a variable camshaft (variocam as you mentioned) in it that comes into play right around that RPM.
Rev the engine up and enjoy the boost!
Although I have a '99 C2, under 3.5k there's never much boost. Around 4k it really starts to kick in, I assume it's just the characteristics of the car/engine.
Just drive it in higher RPMs!
ETA: Fernando said it best.
Thanks Fernando,
I was wondering if this was normal but having never owned an e-gas vehicle nor one with variocam, I was kind of perplexed at the non-linearity of the gas pedal. Guess I'll just have to get used to it as I have no problem with high RPM's.
Note you live in Charlotte. I'm planning to move there as soon as I can get my house sold. Look forward to meeting you some day in the future.
It was disconcerting to me at first too because I thought something was also wrong with the car. Especially reading through here you'll see some of the horror stories, but just keep in mind that most of us who are enjoying our cars don't really have much to say so we tend to stay quiet.
As for Charlotte, moved here in 2004 when I relocated for work. Somehow even though I've had opportunities to leave I've managed to stay all these years. Really is an ideal place for this stage of my life and my family. If you do end up heading here let me know if there is anything I can do to help or answer any questions about the area.
I actually worked in Minneapolis for a while when doing some consulting so enjoyed your home state as well. Granted my visits were always in the Spring so it was really perfect weather and people spending as much time outdoors as they can.
I have a 2004 , and the acceleration should be linear and progressive even when you really give it some gas . It shouldn't feel like flicking a switch . If you know someone else who has a post 2002 car you might try driving each other's cars for comparison .
The variocamplus engine does start to sing as the revs come up but it's not abrupt .
same things happens on my 03 C2. It's very linear and consistent when going at higher speeds and RPMs, only noticeable below about 50mph and right in that 3-4k rpm range.
I turned on mine this morning for the daily commute. A strange sound from the front started, like a failing belt or similar (odd considering the engine is in back). Checked the google for a minute, then stepped out of the car to investigate. Turns out the A/C unit on the building 30' away is a bit noisy. The Porsche was just purring its usual 750rpm tune
Enjoy your road trip and drive that Pcar!
