LHAWLI

Need help with a “clunk” sound on my 2016 991.1 C4S with 20k miles.

It is most prominent on 1st gear when coming to a full stop and then slightly on throttle - I get this clunk sound and i also feel something like it’s torquing. If I let it roll in low speed in 1st gear and slightly on throttle I get the clunk and as soon as I remove foot off throttle it clunks back again. If I keep pressing on/off throttle I get the “clunk clunk” as if there is play and you feel it as if something is lose that’s shifting and going back into place.

It sporadically does it in second gear but barely noticeable however it happens always on first gear and on launch control when shifting from first to second gear, you get this bang.

After an inspection and test drive with chief mechanic this morning.
- engine mounts normal and they go from semi-solid to solid when in sports or sports plus
- transmission mounts checked fine
- guibo flex wasn’t checked but he was convinced it was not that.
- wheel bearing were ruled out after doing alignment

All in all, the Cheif mechanic heard and felt everything I described during our test drive and he said it is absolutely normal and part of the inherent quirkiness of the PDK gearbox. He said it’s solid and built to last and not all 911 are the same even same year production could have different character.

Somehow I am relieved but not convinced but hey, at least it is under CPO.

I do welcome and appreciate any guidance or comments from you esteemed bunch.

991.2.GTS.SF

I have noticed the same thing from time to time, when slowing to a stop at a light, then starting to lightly accelerate after a light change to green before coming to a complete stop. It is almost as if the auto start/stop is on the edge of engaging but catches itself. Has only happened a few times driving in the city, other than that no PDK issues at all. Will likely get it checked out before my Factory Warranty is up in late spring

Jack F

Rolling to stop shortly after cold start, a clunk is not uncommon from PDK in 991.2 4 GTS.

LHAWLI

That's exactly my case as well. I have no issues with PDK at all, it runs well and blows my mind when pushed hard. But as you said, when slowing down to a stop, PDK shifts itself to 1st gear and as you press on the throttle, you feel that "jerk" and not in a good way kinda jerk before the car is like oh year you want to accelerate now... it's an unsettling feeling every time I come to accelerate coming for a stop.

Jack F

If it happens every time, then I would say that is not consistent with my PDK experience.

Jim M.

Porsche has a procedure to adjust the clutches in the PDK transmission. AFAIK can only be done by a dealer, it's all an electronic adjustment. BUT, it shouldn't be needed on a car with just 20K miles! Talk to your service rep and see what he advises.

WP0

I've got a 991.1. No clunks, but sometimes will have a hard shift into first. The only time I've heard/experienced a real "clunk" was in an older 1990's vehicle, and the universal joint down on the drive shaft needed replacement.