Some days ago, after a 50km highway ride, I went home with my 991. Suddenly, on a low speed (50km/h) street, the car suddenly shaked.
It seemed it did not have enough RPM for the gear selected by PDK. I tried to switch to manual, but PDK did not react... I turned off and on the engine...then manual worked again.
There were no warning lights which went on. This was a strange experience.

Next day I took the car and went for a ride. The first 20km, all went ok, smooth changing gears at low rpm (1000-2000 rpm). Riding at slow speed gave no problems. Until after +- 20km, it started again. The car does not have enough power for the selected gear (by PDK) when it's rpm is between 1000 and 1500. This suddenly happened (I never had any issues with this), and it only occurs when the car is warm.
In the higher rpm 2000+ rpm, there are no (power/shaking) problems.


My Porsche dealer is on holidays until next year, I can't ask them ( for now ).

Any idea's what is happening here?

 

I have never heard of it and have never had that problem. I'd leave it parked till your dealer checks it out. My guess is that you will need a software re-flash.

 

Seems there is a salesman present at the garage tomorrow. He will testdrive my car and maybe he can tell something more about this problem...
I hope it's nothing serious...

 

Internet diagnoses are a dangerous thing... but I'll give it a shot!
Sounds like a misfire usually either spark or fuel related, most likely cause these days: a bad coil, injector or high pressure fuel pump - easy for the dealer to find and fix.

 

Update: Salesman drove the car. It only happens when oil temperature is above 95° celcius.
He thinks it's the flywheel (which could have been overheated). Stange....
Next week the mechanics are there and then I will exactly know what it is.