I know I've seen a thread on this before, but I'm too lazy to look it up so hopefully I can get some good info here.

Last weekend after cleaning my car (which involved a couple starts where I just moved the car a couple of feet before I turned it off), I noticed when I was driving off that the car was lurching/rocking fore and aft when I was in 1st and 2nd gear. It was very annoying and embarassing because it was like the sensation you get when you are about to kill it in 1st, but you just barely save it.

If I drove harder (revs >4500 RPM's) on shifts or if I was in a gear > 2nd then the problem went away and everything was fine. After about 10 minutes of driving the problem was gone and hasn't happened since.

Does anyone know what the heck this was all about?

I started to worry that maybe I got some water in the exhaust when cleaning the tailpipes and that might have caused it, but other than that I can't explain it. It wasn't even cold that day either (maybe 65 degrees or warmer).

 

Do a search using "engine hesitation" and you will find the threads. Problem seems to go away by itself usually after a couple of episodes. As far as i can tell, nobody has come up with an explanation. Seems most likely an issue related to fuel.

 

Did you have Sport mode engaged - I have found that the remapped throttle you get with Sport mode can sometimes cause this.

 

In your case, since you just washed the car, would it be possible that some water got into the air-intake of the engine through the vents on the trunk (or rear-hood in 911 term )

With best regards,
- Alex. 07 997S

 

This hesitation problem has happened to me 4 or 5 times between 10000 and 23000 miles, usually on about a half tank of fuel. It always went away after a short time and there never were any check engine lights. No one has any explanation for it and Porsche does not acknowledge that it occurs.

 

I always buy the same fuel from the same station and this happened to me last week for the very first time.

It did however, go away and has not come back. I have 6K miles.

 

I remember I have read in forums about other cars (VWs....Passats, etc.) where the driver starts a (stone dead cold engine) car, backs it out of the garage ( runs for only 40 seconds?) and washes it. Driver then attemps to start the car and the car won't start or starts with difficulty and runs badly for a while. Could it be that the engine programing is not set up to handle such a situation?

 

This sounds more like unburned fuel from the very rich mode of the cold start cycle fouling the plugs due to the quick turn off of the engine in the very early stages of cold start or something to that effect...