Hian

Had a same issue on my 991.2 C2 here in UK,, had teh car from new from March 2016. After 18 months of ownership, driving home one day and after stopping for fuel the coolant temp shot up almost instantaneously giving a red error message. Got it to the dealers and after a couple of days they could find no issues/leaks but needed topping up with about 1L of coolant after bleeding the system. I've had the coolant reservoir recall done. Car has been fine for the last 4 months then went in for its first service yesterday, and picked the car up after work, drove about 100m and had the red error message again and coolant temp off the scale. No way the car could have warmed up in that short drive, so returned immediately to the dealer, who have kept the car. Report today is that the cooling system is performing as expected and that they suspect a vacuum pump on the turbo exhaust(?) - I could be wrong as it was a brief call. Anyway, they plan to replace the suspect parts tomorrow so I'll confirm then what they did, but no mention of COV/reservoir sensors.

zoiks

Is the general consensus that if the issue is with the sensor in the reservoir the car really didn't over heat or have low coolant level it was just a false reading? Thanks...

GreginNH

I got the same message today during the first 5 miles of my commute. The oil and coolant were not even up to temp yet. I pulled over at a rest stop and waited a minute. The car would not start. Waited another minute and it started. Water temp was 185 and oil was 165. Go figure.

GreginNH

My car is back at the dealership for the third time. The coolant reservoir was replaced on the second trip. Of course, they can’t get fault to replicate. I will be picking it up next Wednesday

GreginNH

The dealer found coolant in the vacuum lines. Porsche instructed the dealer to replace all those lines. I got tired of waiting and purchased a new C4S.