This may in fact be the case. Forget where I read it, but Germany is complaining that they do not hear enough back from dealerships and mechanics here. If they don't hear about a problem, they think everything is fine. Like Scat said, no error codes = no problems, and techs nowadays are not savvy enough to troubleshoot. Could be a Catch 22 though, because Germany is looking for an error code to troubleshoot -- probably the same for PCNA. Someone had suggested a letter to PCNA - might as well send one to Germany as well.

Update! I had sent a physical letter to PCNA a week or two ago. Well I got a call just now! The lady from PCNA said she is going to be calling my dealer to figure out basically why they logged the problem but were unable to resolve the issue for me.

This could be fun...

Aside from the obvious 2500 stumble, I wanted to confirm that my fishing line sensation wasn't a figment of my overactive imagination (as I've been told numerous times by the good people at Porsche).

So over the weekend I found a very long stretch of a resurfaced road and oh boy, is it evident when the road is as smooth as a baby's bottom.

Given the stiff suspension of my SPASM, it is very easy to mistake the subtle "small fish tugging on a line" jerking sensation as just being bumps in the road.

If you're planning on taking your car in for this issue, make sure you find the smoothest of roads.

For those who think it's no big deal, you will certainly rue the day that you experience this with your car. This problem can occur after any number of miles driven. Sadly I was struck at 4000 miles.

My latest on this:

- PCNA rep called the local dealer, dealer was surprised it was still an issue for me (wtf?), and then determined to get me in touch with the PCNA field rep. Will schedule a time to meet him there.

- Yesterday on a long drive it was pretty bad how the hesitation affected my acceleration in highway passing situations. Very obvious. Then cruising at constant speed was less than smooth. Unfortunately this problem still plagues my otherwise beautiful car.

I find it a big issue on the highway since I'm in 6th gear quite a bit (I find 7th gear to be too tall which accentuates the lack of torque when passing or when climbing an incline). 6th gear puts the car in the "crap" zone around 65-70 MPHs. Any time the highway has a sight incline, and the engine is under moderate load, I can feel the tugging sensation.

Please keep us updated and keep the pressure on PCNA now that you've got their attention.

Here's my take: For some unknown reason (to us anyway), some 911's experience a stumble or hesitation at around 2500 rpm under light throttle. The stumble appears to vary in intensity or magnitude from car to car. This phenomenon has been observed in the 996, 997, and 991. I strongly believe that the VarioCam system is somehow not functioning smoothly during the cam profile changeover, causing a momentary hesitation when accelerating through the 2500 rpm range, or a somewhat continuous stumble when maintaining approx. 2500 rpm. (Remember, Porsche's literature concerning the VarioCam system states that the transition should be seamless, i.e. the driver should not notice the changeover).

I honestly believe that Porsche is aware of the issue, but simply refuses to acknowledge it. The company line is deny, deny, deny, and if you can miraculously get them to admit they can feel the stumble, then they change to "perfectly normal, they all do that." Got to admit, these guys are good.:mad:

There's got to be a tech or engineer somewhere out there that can find the answer to this mystery. It's a shame that a relatively minor hiccup can spoil an otherwise magnificent automobile.

/\ /\

You hit the nail on the head...

Excellent summary!
:)

I'm not trying to minimize the severity of your issues, but I can't help but wonder if you went ahead and used the no-torque seventh gear, if maybe that would reduce the crap zone? I was driving home yesterday, stuck behind a Honda on a long entrance ramp, and I left the car in third, putting me around 4K RPM. That's a fun area, lots of torque, great sounds, and probably out of the "crap zone". But you can't tool down the highway at 4K for too long before you start to go a little mad. :eek:

I have 2600 miles on my 991 C2' no symptoms of a stumble since purchase. I also have the software update & no stumble before or after.

Frank C.

I have a 991 with an 8/13 build date and do not have the problem so far and have 2600 mi. When deciding to acquire, I agonized over lease vs. buy and decided to lease. It seems with a known problem like the "stumble" it won't be long before it becomes common knowledge to average buyers seeking a pre-owned vehicle.

For all the reasons I considered to lease and not buy, the issue of a difficulty in resale was not one of them. It seems now that leasing makes more sense, especially if there is a known design flaw that the manufacturer fails to recognize. Drive (via leasing) the car for 27 months and get a new one in 24 months or get out altogether in 27 mo. Leasing also provides downside protection against "damage history" reducing resale value.

I am very disappointed to hear that this is happening on such a wide scale. It truly concerns me as a first time 911 owner/lessee.

I'm not sure how wide scale this is. There are a few of us on this board who are talking about it. It might also be fair to say the issue could be subtle enough for some that they don't realize it's not supposed to be like that.

The only thing we can do is continue to bring this issue into the open, both here on forums and with our dealers and PCNA. I would recommend anyone with this issue write into PCNA directly like I did. I sent a physical letter (not email) and I feel that put some more weight behind my complaint because I actually received a call from PCNA. They are in the process of taking (slow) steps to address my problem.

Great job taking that route. Keep us posted.

Folks, none of our cars were born with the stumble.
It can develop at any point, hence it may simply be a matter of time before the problem becomes more wide scale.

I would like to know if everyone with a stumble followed the US breaking in procedure..