Hi guys,

I am new to the forum, and unfortunately, I have an urgent problem.
I have a 2018 991.2 Carrera Cabriolet.

Three weeks ago I was driving through the town and suddenly noticed that the water temperature was 120c. The car gave me the notice to immediately turn off the vehicle to cool down. Later, I double-checked the coolant water, it was at maximum.

I was driving a couple of times more, before going to service and the temperature was stuck at 90c (the middle).

On Wednesday, I had a service performed, and they said they have changed the water pump. By the way, they told me that, I got the feeling that they had absolutely no idea what was wrong with the car. This morning, the same happened. The temperature went to 120c and I had to turn off the car. The car was off for 20 minutes and it worked perfectly later. I am not sure, but I believe that both time the car overheated I was in Sport mode. But I am not 100% sure.


Does anyone have any idea what could be the reason behind all this?



Thanks a lot,
Ivan

 

probably a COV failure, that's fairly common on these cars.

the water pump would physically leak.

with regards to the "staying at 90c" -- the gauge is programmed to display 90c when the coolant is anywhere between some pretty huge range -- 80.3c to 110.3c. I have a writeup on how to fix this.

 

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

here's the big thread on COVs.

 

Could maybe also be a defective thermometer, although I have no idea if that can be an issue on a 911. I had this issue on an Audi S4, it would say the car was overheating but it wasn't, the thermometer was not working properly and had to be replaced.

 

FYI, 991.2 motors don't have COV's. That was a 991.1 issue. It sounds like there may be trapped air in the system. The cooling lines are very long and the radiators are fairly large so it can be difficult to bleed the system. See if your coolant needs to be topped up, otherwise, take back to the dealer.

 

Oh ****, and here I was thinking this whole time it was all the 991s. Thanks for the correction!

 

Actually, if there is an air bubble, he could simply remove the coolant reservoir cap..... start it up and let it run a bit. That should burp out any air that might be trapped in the coolant system. Matt Armstrong did that in his GT3 build, when it kept overheating. Granted different engine, but the principal holds up.

 

Agree.

Also, It's not as simple as just opening the coolant cap while running to burp the engine. They really need to be vacuum filled.

 

Best to use one of the vacuum systems to fill the coolant on these. There are just too many hoses and spots for air to get trapped that simply leaving the cap off to burp it doesn’t work as well as a lot of cars. You can try, but be prepared to repeat many times and spend hours trying to do what would take minutes with the proper tool. Hell, even with the vacuum tool it can still be a pain to get all the bubbles out. It’s definitely one of the more non-DIY friendly aspects of what should be normal care.

 

Matt did the vacuum fill method quite a few times using the right tool, and it still had the air bubble. Then he raised the rear of the car to make the air pocket rise in the system, took off the cap, started it and the air pocket burped out. I think it was in video 4 or 5 of his series on the GT3. At times, simple solutions do work.

 

im agreeing with raising rear of car idea to let air escape,,,cheap fix if it works

 

Thanks, guys for all replies. To me it’s most likely a thermostat. Since I am coming from a very small market, our services are not so great.

 

Is there a video on that?

 

I mean, do you have a link?

 

If you are talking about Mat Armstrong, I’ll look at part 3 and part 4