DavidL996

I am a new member of this board, but have been reading it for some time. I stumbled onto this site while doing some research on a problem I am having with my 2003 996 Coupe. I hadn’t yet posted because I’ve had the car at my dealer with hopes that they would fix it. After three trips in, I have given up on them and am looking to the knowledgeable community of P-car owners for help.

This is my third Carrera. The first was a 1986 Carrera Cabriolet that I bought in 1994 with 15,000 miles and the second was a new 1999 996 Coupe. I have driven these cars many miles, love what they are about, and hope I am lucky enough to own them the rest of my life. My experience with the ’03 is making me question this desire.

I took delivery of the car in December ’02 and have driven it about 8,000 miles. When I took delivery I immediately noticed a split-second surge at around 3,200 RPM when accelerating slowly to moderately. The surge interrupts the normally smooth acceleration. It almost feels like someone is giving the car a shove from behind. When I’ve got a passenger on board, I can actually see the person’s head move backwards even though I haven’t increased pressure on the accelerator. After three or four months of driving I began to notice that the car stumbles for a split second at around 2,800 RPM when accelerating slowly to moderately. So, occasionally when driving, after my foot has released the clutch, the car will stumble, then accelerate smoothly for about 400 RPM, and then surge. Yikes.

I should add that when I drive the car hard, it is a work of art. Unfortunately, I often commute in the car and am stuck driving calmly. I mean, aren’t these the sports cars that are supposed to be as good at getting groceries as they are at the racetrack?

The dealer’s response to all of this is that it is “normal.” In fact, the service manager told me that he can often feel the new cars “buck” due to Variocam II at various acceleration rates and loads. Apparently, Variocam II has variable valve timing and variable cams. The surge that I feel relates to one and the stumble relates to the other. My dealer told me that they even got the regional sales rep to drive the car, and he agreed that what I feel are the valves and cams changing and that Variocam was the only way for Porsche to get 320 horsepower out of the 6 cylinder engine.

Can this be true? I’m having trouble believing that Porsche would intentionally build a car that does not run smoothly. The car is annoying to drive around town.

Have any of you experienced this problem or know where I could go for help? Thanks.

rushing23

This is normal, I think for everyone with these new 996's, including my '02.
I think there are numerous reports of this in the archives--check out the
search engine on this board. Just an excuse to drive it a bit harder--not
needed for me most of the time....enjoy the car.

Karl S

Ask your dealer to drive another 2003 996. I'm sure they must have a few still on the lot. If what you are feeling is "normal", you should get the same response in another similar car. If not, take it to another dealer and see if they can debug it. Between the e-gas and the Variocam, there are a lot of computers and software controlling how the engine runs. These can be faulty and very difficult to troubleshoot.

Karl

Palting

Welcome David.

Yep, the variocam surge, jerk, hiccup, stumble, etc are all descritpive of one of the idiosyncracies that have shown up on the 996. This is in all lines, from the C2 to TT and GT3.

It doesn't bother me much, since I shift below 3200 rpm when I'm drivin' Miz Daisy, and the rpm blows right by without a hitch when I'm driving Dukes of Hazzard. Small price to pay for the variocamII, which gives the car such a wi-ide power/torque band.

russbert

Unfortunately this is "normal" for the 2003 3.6L engine and has been discussed a great deal .... even in other forums recently.

http://www.funcarsonline.com/ubbthre...=5&o=7&fpart=1

BSG03Cab

David,

I too am very disappointed in the surge at 3200 rpm. My 2000 was much smoother throughout the rev range. My dealer has told me it will smooth out in time (I've only got 1900 miles on my car) I also use my 2003 C2 Cab as my principle transportation. Please let me know if you get any other feedback on a possible cause.

Good Luck,
Bruce

DavidL996

Bruce,

I am sorry to tell you that my "surge" has not smoothed out since I got the car, and, in fact, has gotten worse with the addition of a "stumble" in addition to the surge. So far, all of the information I have received indicates that some of us are experiencing a surge, some of us are experiencing a stumble, and some are experiencing both, like me. Certain people say they don't really notice, while others say that it is really bothersome and annoying.

I don't think this problem is one of driver sensitivity, as has been suggested to me by my dealer. I think that all of the cars are behaving somewhat differently; a few new P-car owners are lucky, while the rest of us get jerked aroung on our daily drives.

ShortShift

Some great explanations here for the surge at 3200 when accelerating slow to moderately through that RPM. The surge reminds me a great deal of the difference the 911E and 911S of the late 60s and early 70s showed over the 911T (Base model back then). All three cars had the same basic engine; the power and acceleration difference came from the different cams in each model. Porsche has just exploited their engineering experience by introducing Vario-Cam II. Since it is a gentle reminder of the neck snapping days of the 911S, when it hit its cam at about 3000 RPM and zipped over to redline, I kind of like it!!!

Back then, the cars didn't have much guts below 3000 RPM. Considering the low end torque we have today out of just six cylinders, it is a good trade off.

JeffES

Yes,
Variocam Plus does have a bit of a "surge" or "pulse" when coming online, and that can occur between 2,800 to 3,200. Karl makes an excellent point, however - have your service department check all of the operating parameters with the PST2 to ensure proper Motronic operation. Also, ensure that you are using the lightest weight oil available. The thicker the oil, the less smoothly the "plus" engages.
Good luck,
J

BRUCE

I have been following the "Variocam surge" discussion for a while and I can say that my car does not exhibit this flaw at all. I even try to test it by driving at the prescribed RPM and I get no change in engine response at all. I call this a flaw because I do not think it is acceptable. I have driven many variable cam cars from the Hondas of the '90s to even Fords with a form of variable timing and none of them exhibit a bucking in the engine revs. I know that the Porsche system is very advanced, even more reason to not accept it as normal. One of the beauties of my car is the butter smooth feel of the motor as it revs up. It would drive me nuts if it jerked in the process.
Since not all cars have this flaw, I would say there should be a way to fix it. Why is my car different?

MJones

I don't notice it anymore, guess I just drive around it...but it is still there

Jeff 25

For those with the tiptronic transmission there are two factors at work. The surge at about 3000 rpm is of course the variocam, but the "stumble" before that is the torque converter "locking up" which is when it direct couples through to the engine. It took a ride in another randomly selected 996 on the dealer lot to convince me that both are indeed normal. And I never would have thought so, but they were also right in saying I would get used to it, as I have completely.

Palting I think has it right, that you end up adjusting your driving somewhat so it doesn't bother you anymore.

DavidL996

O.k. So a few of us don't feel the stumble/surge, a few of us think the stumble/surge is no big deal, and a few of us think it's annoying. This is precisely why I believe all of the cars behave differently.

The surge on my car is not a sudden increase in power that lasts to red line, which I think might be fun, too. Mine feels like I've blipped the accelerator. If I were to watch my passenger without telling her it's going to happen, I could watch her head move toward the headrest when the surge hits and then toward the windshield a millisecond later. It's almost like the thing comes on and then immediately shuts off.

As for the stumble I feel, it actually happens at an earlier point in the rev range and on some shifts I get the stumble and THEN the surge. Now my passenger's head is really bopping back and forth.

Frankly, it's embarrassing.

Palting

David,
What happens if you simply accelerate harder, plan on shifting at about 4.5 to 5k rpm? On my car, and I gather from the other posts same on their cars, the burp/hiccup/stumble/jerk/misfire is not noticeable on harder acceleration.

In addition, and this one I don't know about the other cars, I cruise at around 2.8 to 3.5K rpm, and I feel no stumble when going gently up or down on a more or less steady highway cruise.

DavidL996

Palting,
Under harder acceleration the great is wonderful. My frustration revolves around the 70% of driving time I spend in the small city in which I live where 30 and 35 MPH speed limits are the norm and the most serious crime we have is the errant "excessive acceleration rate" of various otherwise law-abiding citizens.

I have no problem with performance cruising on the highway at 2.8 to 3.5 K. It is the constant up and down between these two around city streets where the car underperforms.