lazlo9

So all has been great and I am around 3000k. Suddenly the car started doing this strange power surging after being fully engaged in first gear... and even with a steady foot on gas it kind of surged in waves as it went up in RPM's and continued doing it in 2nd gear. this only lasted for 2 car trips and then it seems to be going away. any thoughts what this might be? Oil is full. and gauges are normal. I thought maybe fuel but I'm half way through a tank of 91 (as usual) and so that seems unlikely.

Edgy01

Tiptronic or 6-speed?

OCBen

Sounds like the condition that's been frequently reported and covered in great detail.

Do a search using "hesitation" as your keyword for links to the threads and related threads that cover this in detail.

andre5

Same thing happened to me at about 2100 miles on my '06 997S manual. My dealer tech told me that he's heard of this "phenomenon" but reports that officially there is no fix. He seems to think that it is software related and that Porsche Germany will address it at some point via an ECU flash.

BTW, it only happened to me once and has not happened again some 1500 miles later.

Coochas

Definitely sounds like the hesitation issue - as OCBen said, search on hesitation/hesitate etc.
Basically,
1) Car jerks around 3000 rpm
2) No CELs come on
3) Usually self-corrects in short period of time
4) Good amount of anecdotal evidence that pulling over, turning car off, and opening gas tank cover, then starting while open hastens resolution of the problem.
5) Other anecdotal evidence that it occurs after switching gas brands or when tank is/has been low.

I have had it occur twice, both episodes lasting about 5-10 minutes IIRC, then self-corrected. This is over 6200 miles total.

As Andre5 points out, Porsche knows about the problem but as far as I know it's unofficially known and there is no definitive known cause or treatment.

kauai_diver

Had it happen to me too few months ago around 4k miles. I attribute it to a "learning experience" in the engine management software. There was nothing I did different for this to happen (that I was aware of), appeared to happed out of the blue on my way home from work and has not happened since.

etmorcus

I had this problem a number of times+. so many that I got the Porsche Regional Service Manager and Sales Manager to see the car. the Regional mentioned that what he did was reset everything back to factory spec and that when th4e cars are shipped they are "detuned". reinitializing everything took care of the problem. It sounds like hocus-pocus. At least in 4000 miles it hasn't returned.
Was it a PITA thougt and scary!
Contact Porsche NA-they will get someone involved if your dealer can't fix it. Have them talk to the So Cal Regional Service Manager-I don't remember his name...

jnx

The "cars are shipped detuned" Where did you get that info? Regional SM? I have never heard that before.

Edgy01

I'm sure what is meant by that is that the cars are shipped with highly restrictive conditions imposed upon them. For example, they can't be driven over a certain speed,--something like 25 mph. It to keep the Ferris Bueller's Day Off scenario from being repeated during the shipment process. With today's stevedores, it's doubtful that there is such a problem.

cdodkin

Could be a feature of E-Gas?

On my last BMW MINI Cooper S, they had a ten month saga where the software for the E-Gas gave a surging or yo-yo effect, even though your foot was accelerating smoothly.

It was all about the software, the self learning of the system, and all related to emissions in CA.

If you 'reset' the software, the problem went away for a while, then came back again!!!!!!

We had to live with it until an 'emissions related' software update recall was issued for the cars.

After that it went away completely.

lazlo9

thanks. it did go away but still is a bit of hesitation at times. I think it's working itself out!

Luke

If it is only happening now in cold weather, seems like it would be a ign. retard or something. What altitude are you guys at? I see the dude in LA. So... if it's sealevel-ish with a dense 02 charge, maybe that is at the root of it?!?!?

H20NOO

It's happened to me twice. The first time I was on the freeway late at night in 5th or 6th gear and the surging was so abrupt, I didn't think I'd make it home. After a few miles, it returned to normal.

About 3 months later, I had the same problem at lower speeds. I shifted into 2nd, 3rd, 4th gears, tried full throttle, partial throttle, run to redline ("Italian tune-up"), etc. Nothing made a difference so I pulled over, shut the car off, waited 30 seconds, re-started and the problem was completely gone.

I reported this issue to my dealer during the last visit and they said they had no ideas and hadn't heard about the problem. Of course, I can't duplicate it for them so they aren't interested. I attribute the problem to an engine management - drive by wire - software hiccup. The electronic nanny is having a fight with herself over throttle position relative to some other measure like mixture, traction control, ignition timing, or who knows what.

It does feel similar to a fuel starvation condition or vacuum problem but the fact it's cured by ignition kill/reset makes that less likely. I'm at sea level or just above it and temps here in the San Jose area are very mild. Both times, the air temp was probably 50-60 degrees F.

MC

500

Had the same problem with my 06 E55 as did other E55's, it was not fuel related, the car gave no codes and the dealer had not a clue nor did MBUSA's district service rep. Eventually my car stalled completely and would not restart so it was towed to he dealer where they were finally able to trace it to a loose wire to the fuel pump.

Bum

I just had this happen on my 06 911S at 8700 miles. I had 60 miles to go on my current tank and I was actually heading to get gas. The car ran fine during the day and I had already driven it 20 miles that day. I decided to put different gas in the car(Shell versus Chevron) just to shake it up a bit. The next day I still felt some residual surging so I set an appointment to take the car in the next morning. I decided to drive the car to see if it would act up on the way to the dealership, but it ran like a champ. The dealership(Carlsen) checked the computer and there were no codes and no surging experienced during their test drive. I told them I would bring it back if it happened again and I have not felt anything so far.
Just wanted to update the thread in case others experience the same.