C6 Corvette Hot Temps
Thread Starter
Intermediate
Joined: Jul 2017
Posts: 43
Likes: 8
From: Modesto, CA
C6 Corvette Hot Temps
Hello All,
My dad was driving his C6 and he was about 30 miles from home and the car displayed the hot temp/ac off message. The car recently had a new thermostat (stock 180 degree) installed plus the entire cooling system was flushed. He drove it back the 30 miles and we let it sit. Tried to start it up and it took a good 5 seconds and the idle was funky and still displayed that same message.
The car has been acting up and it will go to 149 degrees max and then stop increasing the temperature. The dealer we take (took) our corvettes too said they weren't sure what to do. Not sure where to go from here and we are hoping he didn't mess anything up with the motor.
My dad was driving his C6 and he was about 30 miles from home and the car displayed the hot temp/ac off message. The car recently had a new thermostat (stock 180 degree) installed plus the entire cooling system was flushed. He drove it back the 30 miles and we let it sit. Tried to start it up and it took a good 5 seconds and the idle was funky and still displayed that same message.
The car has been acting up and it will go to 149 degrees max and then stop increasing the temperature. The dealer we take (took) our corvettes too said they weren't sure what to do. Not sure where to go from here and we are hoping he didn't mess anything up with the motor.
Thread Starter
Intermediate
Joined: Jul 2017
Posts: 43
Likes: 8
From: Modesto, CA
Alright. Pulled the battery and let the car drain fully. It started a bit funky at first but idled fine. Every start up after that was good. Gonna take it and have it looked over just to be safe. Pretty sure the hot temp/ac off message made the car go into limp mode and had to be cleared before it would start up fine again.
Safety Car
Joined: May 2016
Posts: 4,641
Likes: 1,828
From: Erlanger, Kentucky
More than likely whoever did the coolant refill, did not get all the air out the system. Because the Corvette is so low to the ground, it is very easy to have a lot of air trapped in the cooling loop but it look like it is completely filled. That's why it overheated.
The most ideal way to refill the system and get all the air out is to use a vacuum fill system.
I don't have that kit so I did it the old fashioned way the last time I did a flush in my car. It took at least an hour or more of filling the reservoir, starting the car and letting it run for just a minute or two, turning the car off, and adding coolant. You do that over and over until you can't add coolant. Even once you get to the point of not being able to add coolant, you need to check the coolant level for the next few days as there will be trapped air that will work itself out.
The most ideal way to refill the system and get all the air out is to use a vacuum fill system.
I don't have that kit so I did it the old fashioned way the last time I did a flush in my car. It took at least an hour or more of filling the reservoir, starting the car and letting it run for just a minute or two, turning the car off, and adding coolant. You do that over and over until you can't add coolant. Even once you get to the point of not being able to add coolant, you need to check the coolant level for the next few days as there will be trapped air that will work itself out.
6th Gear
Joined: Jun 2018
Posts: 6
Likes: 0
That hot temp a/c off message is just a scary display for customers to actually take action, very common for any Chevy vehicle. Doesn't actually mean you're car overheated. Typically this is message comes up with DTC P0128, which states a "thermostat" problem, as in it is stuck open and didn't get to operating temperature. You say it got to 149 degrees and never got hotter, so it never overheated, as far as the computer knows it is stuck cold. The computer wants to see it reach "operating" temp within a given time. Sounds like the new "180" thermostat is opening too soon. Change the thermostat.
Race Director
Joined: Sep 2009
Posts: 11,338
Likes: 2,438
From: Eastern
It's most likely air in the coolant system. With the car cold, remove the resevoir cap, and add coolant (Dex-Cool 50/50) to the top of the resevoir neck. Start the car and idle.
The level in the resevoir will drop as it adds to the system. Refill to the top of the resevoir neck. Do this until the level stops dropping. Replace the cap, take the car for a drive. Let the car cool, then recheck the coolant level. If it is below the Cold mark, add mor coolant to the system.
I've added a PDF from the Service manual.
The level in the resevoir will drop as it adds to the system. Refill to the top of the resevoir neck. Do this until the level stops dropping. Replace the cap, take the car for a drive. Let the car cool, then recheck the coolant level. If it is below the Cold mark, add mor coolant to the system.
I've added a PDF from the Service manual.
