XLOR8T

I was driving my 991 C4S Cab yesterday and it just popped up a "Cooling System Error" . car has 2900KM on it, anyone else have this come up? called service and they said if it's not overheating it's ok to drive untill I can take it in today or tomorrow.

yxc145

I had one. took the dealer 3 days to find the problem. There was a small split/leak at the rubber tube connecting to the exhaust system

XLOR8T

Same exact problem here! Thanks for the reply

CMR

After driving my 2013 CPO C4S (13,000 miles) for only four days it displayed the cooling system error. It has now been in the shop for almost two weeks. Apparently there was a campaign to replace the original change over valves in certain 991's due to weather seal leaks, and while my car did have that done, the dealer believed that the replacement valves were failing. The dealer subsequently replaced them all with the most up to date valves (ending in F) as well as the PDK and "neutral" valves. Despite this the error still appears after driving the car. They have tested each and every valve and the thermometer and are convinced that they are all working properly and that the error is a software issue. They are waiting to hear from the Porsche help desk with regards to working out the software issue in my care. Does anyone have any advice? Thanks in advance.

Vic and Ray

here's a link to a link ....

https://rennlist.com/forums/991/836119-check-light.html

Had same problem. Fixed and no recurrence yet....

CMR

I read your post and my dealer has already replaced all the valves with the F series and the car still displays an error. While they are now blaming the error on computer software, I'm not convinced.

Vic and Ray

Check valves and associated tubing are the weakest link in this scenario.

I wonder if one of the newly installed check valves is intermittently faulty. Possibly bad tubing and a persistent small vacuum leak? You would hope that 2 weeks in the shop would find that.

Do you have any current symptoms that could be attributed to a faulty check valve... like PSE or sound symposer stuck in one mode or low or no cabin heating?

Sounds frustrating chasing these gremlins...

Second opinion from another dealer soon?

CMR

Vic and Ray,

I have standard exhaust but I've gotten a couple of comments on how loud it is. On another forum, a member recommended checking the vacuum hoses as he had a loose one which led to the cooling system error and an increased exhaust note. I'd hate to think that the service department didn't check those hoses. I don't know if the heat in the car works since it was warm during the four days I drove the car.

I'm guess I'll wait to hear what Porsche recommends to the dealer early next week. I'd hate to have to take it to another dealer. But my patience is wearing thin.

CSK 911 C4S

When I received the same error message as you I noticed I lost all my heat as well which helped the tech narrow down which little valve/switch went bad.

CMR

My service advisor just called me and told me that they found the culprit. One of the replaced valves went bad. Sad to say it was an early "F" production valve. They put in a new one and the car is apparently good to go. With my permission they are having one of the techs drive it home tonight and return it in the morning to make sure that the error doesn't return on a more substantial test drive.

Lucky guy....