I had to take the Panamera Turbo in to service just a few weeks after buying it CPO from the dealer.

We were driving home from the ballgame on the freeway and all of a sudden I couldn't accelerate without the car shuddering like we were driving over grooved pavement. Engine was running and everything seemed OK on the dash, but any attempt to accelerate was met with choppy, jerky throttle response.

A few minutes of this resulted in "PSM Error" and "Auto Start/Stop Deactivated" messages on the screen. Got us home, restarted the car in the garage and it seemed happy again, so I wrote it off an odd behavior from a used car.

Next evening, car starts very lumpy in a parking lot after dinner and PSM errors come right up. Restart, car is happy enough to get home again, but struggling a bit and not smooth. I get it to the dealer the next day and, of course, the drive and test w/Service is flawless, so no giving up the secret to them while I'm there.

Just got a call from Service this afternoon with a report of "misfires" reported in the error logs, and they're looking into it. Hmmm.

Also, I reported a squeaky front suspension and they found sway bar bushings in need of replacement. Car has 53k on it, right in line with other's reports of squeaky front ends.

I'll post tomorrow's report from Porsche Service when I hear from them.

 

Spoke w/Service today and learned a few things:

- Sway bar bushings are a part swap- no big deal, but did have to be ordered.

- Asked for a 4 wheel alignment, learned that the ACC/radar cruise control has to be calibrated afterwards, which requires a particular tool, which has to have a particular software on it and older cars such as my '10 aren't compatible. A special tool with 'old' software on it had to be requested from PCNA and hasn't arrived, so an alignment has now caused a cascade problem.

- Misfires on the engine, of course, can't be replicated, so a bit of spark plug and coil swapping was done along with some test drives. They can't find anything wrong and there's no root cause to the PSM errors. So, I'll take it back and drive for a while waiting for the problem to happen again.

Don't'cha hate it when an engine problem can't be diagnosed?

 

Yes - yes I do good luck - I'd love to hear this all get worked out! thanks for posting.

 

An update, for those following this saga.

Heard from Service on Monday, now 6 days in the shop, that the ACC calibration had been completed and that they had replicated the misfire. That's good, in that the engine is running rough and it's not just me noticing it. I'm told they're "swapping parts around to isolate it", which i think means they are moving coils and whatever around, trying to get the misfire to follow a cylinder or a coil or something like that.

I hope to know more Thursday.

 

Final report, since I picked the car up yesterday.

The techs diagnosed a bad coil and spark plug by clearing codes of misfires on cyl #2, putting the plug from #2 into #1 and the coil from #2 onto #3. The misfires followed the coil to #3, so they replaced it and the associated plug.

Parts replaced, from the service report:

1 948-602-104-13 PENCIL COIL
1 999-170-228-90 SPARK PLUG

I have to admit- the engine is noticably smoother and the power comes on with more authority. I think there was a stutter in there before that, now that it's gone, is obvious.

Hope this helps others out there who run into something lie this.

 

that's good news that it was taken care off and you can fully enjoy your car. congrats on issue resolved.