Hello all,
Here is the issue. I have a 2014 C7 with 58k on it. Last week the car started overheating on me and one day spilled all of its fluid on the street in front of my house. After reading many of the forums, I have done the following:
1. Replaced the thermostat which was stuck;
2. Changed the oil-no coolant in the oil;
3. Changed the coolant and burped the system-No oil in the coolant;
4. Made sure to not overfill the reservoir like I did previously.
5. Fan works.

Took the car out for a drive today. Temperature outside 102 degrees. Car drove fine both directions getting up to 212 before cooling right back down to 206 to 204. Stopped the car at the bank and no issue. Drove home again with no issue. Once I pulled in my driveway the temp went to 212 and then back to 210. I stopped the car and fluid began to shoot out the tube. Decent amount of fluid came out.

Any thoughts as to what I am missing.

 

Overfilled? Sounds like everything else working as it should.

 

Those temps seem reasonable. Why it is spilling coolant - .


Hope you can find what is going on.

 

Those temps should not be the reason you are have coolant pushing out of the reservoir. As long as you have properly bled the coolant system, (making sure the heater blows hot) you should be fine. Suspect the radiator cap as the issue.
Good luck!!!

 

I agree. It sounds like the radiator cap isn't maintaining pressure so the cooling system boils over when you stop the car. Also did you use a 40/60 mix of coolant/water as directed by the OM?

Bill

 

If all else fails, try vacuuming the system to remove any 'trapped' air.

If you have a pocket of trapped air in the engine it will start to boil as soon as you run or turn off the car depending on hard large the air bubble is.

Check your overflow tank, any bubbles appear when the car is at normal temp and running, if so could be a blown head gasket and this will lead to a bolt over condition.

 

How high did you fill the coolant reservoir? It you topped it off to the brim, that's your issue. The "full" mark on a C7 is not where you'd expect it to be....it'll seem low.

 

Radiator cap is stuck open, allowing coolant to be pushed through the overflow

 

I have had my 2014 for 9 years and it always runs at 202-212 with 64k miles

 

I didn't see where OP told us if he has the basic wet sump motor, or the Z51/GS/Z06 motor with the dry sump and oil cooler.
Our car is a Z51 with the wet sump, coolant temp runs right around 190' (thermostat temp) in normal summer driving.
OP is above 4,000' so plain water boils at about 205' there, of course DexCool and a pressurized system should raise that.

 

Here's what happened with my 2014 Premier Edition.

The coolant surge tank (up by the passenger windshield) cracked while I was slowly climbing a mountain (inside a subdivision) and dumped out most of the coolant. I (stupidly) had it to "Adventure Chevrolet" in Dalton, GA which was the nearest dealer. They said it needed a new surge tank, water pump and thermostat which I authorized - because it was over an hour away from home and I needed the car drivable. They charged me $2,000 for that and declined to do the hoses when I inquired about that.

Fast forward another month. Decided to take it on a short trip up into the mountains with another friend and her C8. Driving it hard, the temps skyrocketed and the car went into limp mode and shut off the AC. I checked and there was still coolant in the surge tank so I limped it back home and decided to tear into it myself. I replaced the two main radiator hoses because the car is 9 years old. I also replaced the new 207 OEM thermostat with a 180 from Granatelli Motorsports. Bought a Mishimoto vacuum fill/purge kit but couldn't get the system to draw a vacuum.

The next week, I was tired of fooling with it and got it over to a friends house who is a mechanic. They diagnosed a leaky heater hose (the one with 5 outlets) so we replaced that and then they showed me that there's a small air valve on the bottom of the surge tank that has to be plugged in order for the fill/purge kit to draw a vacuum on the system. With the system now drawn down to 20lbs, we put the fill hose in a fresh jug of Dexcool and drew it into the system careful not to let the hose rise above the surface of the coolant. We drew in a little under 2 gallons into the system and it was filled to capacity. (That kit is slick....I really like it).
Since then - the car runs pretty cool most of the time and has stayed under 236 when ran continuously above 5K. (We ran Deals Gap as a good test). No overheating and no coolant smell so I think we're finally in the clear.

So....some notes for you:
The car is a 2014 so I think you're going to be in the same boat as me and certain things made of plastic and rubber are going to start to fail
At a minimum, I'd probably say replace that surge tank and your hoses. The surge tank got brittle and just cracked open which left me stranded. It's a good item to replace BEFORE it fails.
You might consider doing the water pump & thermostat while you've got the car down. The thermostat has a plastic housing so if you order a cooler thermostat, be prepared to have to install it in the housing. DO THAT WITH DRY HANDS. Mine were wet with coolant and I let the spring fly out which broke one of garage door windows. It's pretty obvious how it goes in once you see it.

My thoughts were - I'm in here - I've got it all apart - I might as well do the WHOLE job right while I've got the car down. I live in steamy Hotlanta so I decided to go to a lower thermostat. I'm not sure where you're at or how hot it gets there, but you will likely be ok with the stock 207. Still, it's a wear item and they fail from time to time, so it'd be good to just replace it.

Anyway - best of luck and ping me if you have any questions.

 

I bought that Mishimoto kit and couldn't get it to hold vacuum either so returned it. Couple of questions:
Can you post a picture or better describe where that air valve is that needs to be plugged?
What did you use to plug it?
Which adapter is the correct one for the Vette in that kit, I wasn't sure I used (think it was the brown/tan one near the right latch of the case)?

 

You see the end of that little black "hose" that comes off the bottom of the tank? - The end of it is on the left edge there. That's what you plug. My mechanic had a plug that fit it...I don't know what was used, but it fit in the end and plugged it up. Once you plug that, you'll be able to draw a vacuum. As far as the Mishimoto adapter, we just looked at the little paper that came with it and picked one of the GM ones that fit. It's kind of a trial and error thing...you've got to try a few to figure out which one fits it best.