elroth

On Saturday 12/4 I was with the Porsche Driving Club Charlotte driving my 2017 991.2 C2S PDK in Sport Mode in the mountains outside Lake Lure and the Pisgah Forest, North Carolina. The vehicle has only 15k miles and the transmission was in "automatic" mode. We had some spirited driving on the mountain roads for about an hour - hour and a half with a couple of 5 - 10 minute breaks in between. I was stopped at a light in Brevard NC on the way to lunch when I got an error message that the transmission was overheated and to shut off the car. Before I could shut it off the engine began to rev wildly going up to 7k rpm by itself. When I tried to pull away from the light to park the transmission wouldn't go into gear. I had to shut the engine off at the light and couldn't move. Fortunately traffic was able to go around me. After about 10 minutes I was able to start the car and drive away. At no time that day while I was driving in the mountains was either the engine oil or water overheated; all the gauges were in the "normal" range. When I got out of the car to wait I could smell the transmission fluid. There were about 20 911's in the group, mostly 991.1's and .2's; nobody but me had any problems. After it cooled I was able to drive the car back to Charlotte about 120 miles on the interstate without incident.


Does anybody have any idea what's going on here? The car is still under warranty. Thanks!

asellus

Knee-jerk response here is going to be COV issues. Giving it to your dealership with this explanation of symptoms will lead them to look in the right places. The self-revving to 7k RPM is a bit of an outlier to me, though.

barncobob

thank you warranty..have ur water pump checked too

elroth

The water pump was replaced last year, December 2020; it's a CPO car.

AdamSanta85

Second this. Almost sure 991.2 has a COV that controls the transmission cooler, 991.1 does.

asellus

It only makes sense given the PDK specifically was problematic but the engine was not (aside from that weird 7k rpm thing, I still can't explain that). It's either that or a controller issue and the clutches are slipping all the time, generating crazy heat... but you'd feel that, I think.

vanlieremead

Why don’t we have trans temp someplace on our selectors? Even my truck has that. These COVs are not predictable, are they?

elroth

Ok - thanks. Now what is a “COV”?

Al.Fresco

https://rennlist.com/forums/991/8002...-on-991-a.html

asellus

Good question.

The trans had sensors you can read with a tool, at least. I think even a generic $7 elm327 OBD dongle with Torque on your phone can access it.

Fullyield

The reason most trucks have a trans temp gauge is for towing. Trucks pulling loads in hilly terrain frequently overheat automatictransmissions. My truck has an additional transmission cooler that came with the “towing package”. While I wish it was an available selection from the factory, the Durametric and Cobb Accessport will both provide live data on PDK oil temps.

CSK 911 C4S

I hope it's a simple fix.

I've beaten up my 991.1 PDK for hours on those same roads without issue to the point the car smells like it's melting.

Jack F

When I pull into the garage and my car smells like that, my wife takes a whiff and says that I had fun.

maschinetheist

I love that smell. That and the hot metal cooling down. I love how they kept that sound in the 992 GT3 reveal trailer towards the end.

snake eyes

The sound of a well driven vehicle!
Best of luck to the operator... let us know the resolution