A warning message appeared on my 2015 GTS yesterday advising that there was a coolant system fault and the warning helpfully suggested that I "visit the workshop". The traditional gauge appears to be fixed at +/- 200F, while the digital gauge varied between 198F-235F. Sometimes it it was very erratic. I was a ways from home, so I watched it as best I could while I drove home. Never saw the digital over 235F and I don't think the traditional gauge moved at all.

I have to get the two recalls taken care of anyway, so I'll call the dealer tomorrow and take it in.

Any thoughts?

 

Change Over Valve.

 

Maybe. Maybe not.

There are a thousand posts on this topic if you search.

 

Although it's hard to tell what it is from this side of the keyboard, statistics do point towards a change over valve, as LexVan says. I had the same issue on my 2012 C2S, and it was a change over valve as well. It's a very common issue. I had one replaced under CPO warranty in April and haven't had any problems since.

 

I had a similar issue this spring and it was a changeover valve. They said something like 3 or 5 of them were broken (heater cov had previously died and been replaced).

 

Link one, and help the guy out.

 

Anyone have revised part numbers for the COV's?

 

Well, it was not a COV, It turned out that the vacuum pump needed to be replaced. Ended up getting the two recalls done, a new set of tires and a few other things as well. They had to order the pump, so it will hopefully be done today. I've spent the last week driving a 2021 Cayenne. As nice as it is, it only serves to confirm that I am not a fan of the SUV/Truck.