My s5 fc vert has been severely overheating today and yesterday (gets so hot the coolant not only comes out of the overflow tank, but also pops from the rad cap itself)

Im extremely worried, and will be bringing it to lucky seven asap, but i was wondering if any of you all had any idea what the problem is? It was 92 degrees today on my drive home and comparable temperature yesterday maybe even a little hotter, i was in very very heavy traffic yesterday but NOT today and it still happened. Almost all freeway driving btw.

One thing to consider is that the car runs very smoothly and drives just fine, and also stays perfectly fine temperature-wise in the morning when its cool out.

But another troubling thing is that the car ran PERFECTLY in hot weather conditions the entire summer. Just now its overheating like this

Please help hahahaha

 

Thermostat?

 

Water pump, t-stat, rad cap itself, junk in the cooling system?

 

Rad cap looks brand new in condition, but its only 0.9 bar. Im gonna have lucky seven check the other stuff over

 

More random details : im on the stock fan and radiator as well.

 

Possible the stock fan clutch has given up or a whole slew of other things, best bet is to not drive it until you can get it checked out by someone that can properly diagnose it.

 

It's the thermostat.

 

+1 probably Tstat failed or you have a blockage in the system somewhere else.

If the waterpump dies, you will have no pressure. If the thermostat is closed after it's warm, the water pump will just endlessly over pressure the system since the hot coolant can't go anywhere.