Looks like your solution to the problem is still the only one.

Hard to imagine in this day and age that a known issue such as this goes unaddressed.

 

Nope, still no solution. I'm still trying to get PCNA to take me seriously and help diagnose the problem. As far as they are concerned I'm just driving my car incorrectly (yes, that was their actual statement) and the case is closed.

 

Relentless persistence helps, as does not taking no for an answer.
I will find a solution to this defect and please remember that the pen is mightier than the sword.

 

Mine is going back to the dealer soon. I let both the dealer and PCA have it on my last service survey and the dealer called me right after that begging me to bring it in again.

 

What a crappy explanation of PCNA. How can you drive a car incorrectly ? Sound like "we don't know, it's impossible, it's your fault" to me.
And if they make a statement like that, they better have evidence, and better still tell you how to drive it correctly.

 

In this day and age where profits are more important than customer satisfaction, Porsche (as well as most other large corporations) will go to any length to avoid costly warranty repairs. There's little doubt in my mind that PCNA has put out the word to all its dealers that the stumble/hesitation problem is not to be addressed. Either it doesn't exist, or they all do it and it's absolutely normal, take your pick. The first time I mentioned the stumble to my SA and head tech it was fairly obvious that they were both somewhat uncomfortable discussing it. Obviously, tap dancing was part of their training.

 

Folks.
Please do not waste your time with the dealers.
They are only there to service your cars and not fault find.

Contact your regional PCNA after-sales representative and only deal with him /her.
The dealership will only do what they have been instructed to do - which is nothing at all.

 

My opinion on this, its that its an issue once all the readiness parameters are made. If you clear the DME the car has to run through a few cycles to get the emissions map on the DME and show ready on a CANBUS scanner. Thats why it comes back, I feel it probably has something to do with the evap canister or something of that ilk or something to do with the variocam. As it happens at the same rpm.

 

@Dave07997S
Your theory on running a few cycles makes sense, but can you elaborate as to why the evap canister would potentially cause a stumble?
Thx

 

My last letter back to them basically told them to send the PCNA regional rep to see me to teach me how to drive. Yes, it was a bit snarky but I was pretty livid with their (lack of) response.

They claimed that the only way this was an issue would be if I was letting off the throttle right when I reached the VarioCam transition point. Yeah, right. The field rep never even met with me in person or drove my car - he just phoned that in and PCNA declared my case closed.

 

If your rep is a certified idiot (which yours clearly is), then escalate the matter to his superior.
After my PCNA tech initially diagnosed my problem over the phone (quite an impressive feat), I simply went back to PCNA and informed them that I refuse to work with this individual. Consequently my problem was escalated.

They cannot unilaterally close a case.

 

Personally, I've never had the stumble issue (knock on aluminum).

But if I did, I would focus on getting one of the major car magazines or at least Porsche-focused ones to write a story about it. For PAG, that would be a major escalation in (reputational) exposure from where things currently stand.

 

I stopped by my local dealer today to pick up a new Porsche hat and spend a few moments with my service advisor. I asked him about the so called Engine Stumble Issue. He told me a couple of the dealers customers have brought their 991's in complaining of engine stumble. He said the dealership could not find any issues with these two 991's. He explained to me that PDK is not an automatic transmission but a seven speed manual wet clutch controlled by the cars computer. He said if you don't apply constant pressure on the accelerator when you are moving from a dead start, you might cause what seems like an engine stumble because the computer is reacting to how you are pressing on the accelerator. Please forgive me if I did not report accurately what he told me but that's how it sounded to me. I don't have the engine stumble issue on my 2014 991 so its hard for me to know what it feels like. I do accelerate aggressively though. Once I put my foot down on the accelerator I don't let up until I reach my desired speed. My question is does the engine stumble occur when you accelerate aggressively or when you take off slowly? Don't get me wrong I am not trying to say that it does not happen on your 991, I am just trying to understand under what circumstances it occurs.

 

The service advisor should be applauded for his attempt to provide a explanation, but unfortunately he has missed the mark.

A few clarifications..
- This obvious defect occurs with both manual and PDK's.
- The problem develops over a period of time (after x,000 miles) and has nothing to do with how drivers suddenly press the accelerator differently from the previous thousands of miles that they've driven.
- No one has reported taking their foot of the pedal to initiate the stumble.
- All variables were addressed in a recent poll. See https://www.6speedonline.com/forums/...y-results.html

In fairness to the advisor, there were some unrelated incidents a while ago relating to PDK's hesitating upon hard takeoffs from standstill. That issue was quite different for the stumbling problem which occurs during constant (under moderate load) acceleration, most evident in 2nd gear.

If you choose to accelerate aggressively, you will most likely bridge the dead spot at approx 2500 rpm, which is not a solution.

If they all stumbled, then and ONLY then would I accept that this car is "operating as intended". PCNA jargon used to dismiss those less persistent than yours truly.

 

Additionally, if you find a long hill where you can hold the RPM steady at the point at which the stumble begins (in my case approx. 2600), you'll experience the "fish tugging on your line" symptom. For some reason, it appears that the VarioCam system can't decide which cam profile it wants to be in.

No way in hell this is a normal or acceptable.