Overheating warning
Thread Starter
Melting Slicks
Joined: Jan 2014
Posts: 2,789
Likes: 500
Overheating warning
I've had a cooling-related problem for a while. My car will be fine for 100 miles or so of normal highway driving, then suddenly, for no apparent reason, the temperature gauge will suddenly go from normal 220° to past 260° in seconds with warning dinging and dashboard warning lights. I'll pull over and turn the engine off for a couple of minutes or shift to a higher gear for lower RPMs and the temperature gauge will just as suddenly go back to normal 220°. That can't be sudden overheating. It's got to be an electrical problem. Any thoughts guys?
Race Director
Joined: Mar 2010
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This is not the Corvette ownership experience we strive for. Our team would like the opportunity to learn more about the overheating on your C7 and investigate ways we can potentially assist. When you get the chance, please send us an email to socialmedia@gm.com. Be sure to include your Username and Forum name in the subject line, then provide additional details about your experience in the body of the email. We look forward to your contact.
Race Director
Joined: Oct 2004
Posts: 13,587
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From: Home of the VOLS ! Knoxville, TN. Tennessee
St. Jude Donor '11-'12-'13, '15, '16-'17-'18-'19
Sounds a lot like what I had in my last C7.
It turned out to be air in the system. At least that's what the shop told me.
I did not have any more problems after they fixed it.
It turned out to be air in the system. At least that's what the shop told me.
I did not have any more problems after they fixed it.
Le Mans Master
Joined: Feb 2010
Posts: 7,798
Likes: 314
From: Santa Fe Tx
I've had a cooling-related problem for a while. My car will be fine for 100 miles or so of normal highway driving, then suddenly, for no apparent reason, the temperature gauge will suddenly go from normal 220° to past 260° in seconds with warning dinging and dashboard warning lights. I'll pull over and turn the engine off for a couple of minutes or shift to a higher gear for lower RPMs and the temperature gauge will just as suddenly go back to normal 220°. That can't be sudden overheating. It's got to be an electrical problem. Any thoughts guys?
GM guys are pretty good. I would just ad that Corvettes are unque in many ways, but one is the owners. Many Corvettes are garage queens, never driven in cold weather......
As such the interior heaters are rarely used and even when they are it is long times between uses.
My thinking is that when the heater mode operates it allows water to go through the heater core which flushes out the water that has been in the core forever. this bad water may have crap in it and clog sensors, thermostates, ect. and so to avoid this I suggest all Corvettes be run with interior heater mode several times a year. Keep the water moving, flushing out the system. my two cents
Racer
Joined: May 2023
Posts: 336
Likes: 198
From: Niagara, Ontario, Canada
GM guys are pretty good. I would just ad that Corvettes are unque in many ways, but one is the owners. Many Corvettes are garage queens, never driven in cold weather......
As such the interior heaters are rarely used and even when they are it is long times between uses.
My thinking is that when the heater mode operates it allows water to go through the heater core which flushes out the water that has been in the core forever. this bad water may have crap in it and clog sensors, thermostates, ect. and so to avoid this I suggest all Corvettes be run with interior heater mode several times a year. Keep the water moving, flushing out the system. my two cents
As such the interior heaters are rarely used and even when they are it is long times between uses.
My thinking is that when the heater mode operates it allows water to go through the heater core which flushes out the water that has been in the core forever. this bad water may have crap in it and clog sensors, thermostates, ect. and so to avoid this I suggest all Corvettes be run with interior heater mode several times a year. Keep the water moving, flushing out the system. my two cents
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Thermostat
Fan
Air in the system (although this is unlikely if it hasn't been recently flushed)
C7 Corvette has constant flow through the heater core. It uses a diverter door to block the heat when not needed. I don't recall Corvettes having a shut-off valve since the early days of the C4 or maybe even late days of the C3.
Fan
Air in the system (although this is unlikely if it hasn't been recently flushed)
C7 Corvette has constant flow through the heater core. It uses a diverter door to block the heat when not needed. I don't recall Corvettes having a shut-off valve since the early days of the C4 or maybe even late days of the C3.
Safety Car
Joined: Dec 2012
Posts: 3,841
Likes: 1,856
From: St. Louis Metro East IL
What year is your vette? Please add some info to your profile.
There was a problem on some 2014s with the fan controller. It is built in to the fan assembly, so the entire fan assembly needs to be replaced. Many replaced with Z06 units. (I had no problem with my 2014).
Here's one of many threads on the issue:
https://www.corvetteforum.com/forums...-to-260-a.html
Ron
__________________
2019 GS Long Beach Red 2LT M7 PDR (current)
2014 Z51 Lime Rock Green 2LT M7 (previous)
2006 Daytona Sunset Orange 3LT M6 (previous)
There was a problem on some 2014s with the fan controller. It is built in to the fan assembly, so the entire fan assembly needs to be replaced. Many replaced with Z06 units. (I had no problem with my 2014).
Here's one of many threads on the issue:
https://www.corvetteforum.com/forums...-to-260-a.html
Ron
__________________
2019 GS Long Beach Red 2LT M7 PDR (current)
2014 Z51 Lime Rock Green 2LT M7 (previous)
2006 Daytona Sunset Orange 3LT M6 (previous)
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Thread Starter
Melting Slicks
Joined: Jan 2014
Posts: 2,789
Likes: 500
What year is your vette? Please add some info to your profile.
There was a problem on some 2014s with the fan controller. It is built in to the fan assembly, so the entire fan assembly needs to be replaced. Many replaced with Z06 units. (I had no problem with my 2014).
Here's one of many threads on the issue:
https://www.corvetteforum.com/forums...-to-260-a.html
Ron
__________________
2019 GS Long Beach Red 2LT M7 PDR (current)
2014 Z51 Lime Rock Green 2LT M7 (previous)
2006 Daytona Sunset Orange 3LT M6 (previous)
There was a problem on some 2014s with the fan controller. It is built in to the fan assembly, so the entire fan assembly needs to be replaced. Many replaced with Z06 units. (I had no problem with my 2014).
Here's one of many threads on the issue:
https://www.corvetteforum.com/forums...-to-260-a.html
Ron
__________________
2019 GS Long Beach Red 2LT M7 PDR (current)
2014 Z51 Lime Rock Green 2LT M7 (previous)
2006 Daytona Sunset Orange 3LT M6 (previous)
Safety Car
Joined: Dec 2012
Posts: 3,841
Likes: 1,856
From: St. Louis Metro East IL
What does add some info to your profile mean? Go up to the top right of the screen where your sign in name is located, click the arrow to expand, select MY PROFILE and do some editing. This is the public profile that others can see. You can list as much detail as you want. It would be really helpful when you ask questions if others can look and see what year, transmission, major options, etc. your car has.
You just click on someone's name to see their public profile.
Ron
You just click on someone's name to see their public profile.
Ron
Thread Starter
Melting Slicks
Joined: Jan 2014
Posts: 2,789
Likes: 500
My Vette is a 2014 with Z51 and a 7M transmissio and 121,000 miles. Thank you all for your suggestions, but they don't really address the the very temporary and intermittent nature of my problem. I can sometimes drive 200 highway miles with no problem. Or I can drive 10 miles and the temperature gauge can quickly (20 seconds or so) go from 220° to past 260°. If I ease up and put it in a higher gear, it can just as quickly go back to 220° and stay there.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
My Vette is a 2014 with Z51 and a 7M transmissio and 121,000 miles. Thank you all for your suggestions, but they don't really address the the very temporary and intermittent nature of my problem. I can sometimes drive 200 highway miles with no problem. Or I can drive 10 miles and the temperature gauge can quickly (20 seconds or so) go from 220° to past 260°. If I ease up and put it in a higher gear, it can just as quickly go back to 220° and stay there.
Melting Slicks
Joined: Feb 2018
Posts: 2,156
Likes: 1,031
From: North Texas
Sensor or thermostat.
Watch the water temp on the performance screen and compare it to the analog screen, they should follow.
Better yet if you have a scanner monitor temp with this also.
WAG, if it appears to be an electrical issue check all grounds and reseat connector on temp sensor.
Good luck.
Watch the water temp on the performance screen and compare it to the analog screen, they should follow.
Better yet if you have a scanner monitor temp with this also.
WAG, if it appears to be an electrical issue check all grounds and reseat connector on temp sensor.
Good luck.
Le Mans Master
Joined: Jun 2002
Posts: 5,034
Likes: 842
From: Rotonda West, FL 2015 Z51 M7 3LT
Oldtimer
Melting Slicks
Joined: Feb 2018
Posts: 2,156
Likes: 1,031
From: North Texas
Since you seem to indicate that your C7 is a 2014 model I'd be suspicious of the fan and its controller.
But since you have indicated that the temp swings wildly and fast I'd lean towards an electrical issues.
Also the 14 model analog gauge really isn't a gauge. Its an indicator that reads low, medium, high. Only the DIC will give you the correct temp.
Connect a scanner, if you have one, and monitor all the PID's that are related to this issue. Easiest and best way to track it down.
If you don't have a scanner first check all your grounds in the engine bay and all battery connections. If this doesn't fix the problem and you just want to shoot the parts cannon at it, start with the temp sensor then the thermostat then the fan and controller.
Good luck and let us know what you find.
But since you have indicated that the temp swings wildly and fast I'd lean towards an electrical issues.
Also the 14 model analog gauge really isn't a gauge. Its an indicator that reads low, medium, high. Only the DIC will give you the correct temp.
Connect a scanner, if you have one, and monitor all the PID's that are related to this issue. Easiest and best way to track it down.
If you don't have a scanner first check all your grounds in the engine bay and all battery connections. If this doesn't fix the problem and you just want to shoot the parts cannon at it, start with the temp sensor then the thermostat then the fan and controller.
Good luck and let us know what you find.
Last edited by Tinkertech; May 24, 2024 at 08:40 AM.
Instructor
Joined: Jan 2021
Posts: 214
Likes: 114
From: Powell TN
Sensor
If you’re getting wild swings with coolant temperatures, it’s not very likely that you’re experiencing an actual overheating condition. It’s more likely a bad coolant temperature sensor. Try replacing the sensor. It’s an easy repair and easy to access, located near the thermostat housing on the top front of the engine. The part is fairly cheap (OEM Delphi found at Rock Auto $24).
Let us know how it turns out please!
Save the wave, don’t text and drive,
Let us know how it turns out please!
Save the wave, don’t text and drive,
Administrator
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I would also think the issue lies in the temp sensor (or the thermostat). Good luck, hope the cause and repair is simple and inexpensive.
Always Shiftin'
Joined: Jun 2000
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From: Central Florida
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Here is another vote for the thermostat and/or coolant temperature sensor.
Both are very easy to replace, and inexpensive. With your mileage, I would suggest changing both out. Even if it doesn't fix the problem it will still be a good idea.
Good luck!!
Both are very easy to replace, and inexpensive. With your mileage, I would suggest changing both out. Even if it doesn't fix the problem it will still be a good idea.
Good luck!!
Last edited by MacA1979; May 31, 2024 at 08:28 AM.
Drifting
Joined: Feb 2005
Posts: 1,445
Likes: 173
From: San Jose Ca
I don't believe a bad tstat could allow a 40 degree temp rise or fall in 20 seconds, so I'd bet on the temp sensor. However, given the age of your car, I'd also ask when the coolant was changed. There are procedures around that describe how to change the coolant and get the correct ratio of water/coolant, so given what I've been through with my 14, I'd change the tstat, sensor, and coolant at the same time. Note that later year stingrays use a cooler thermostat (190 I think) than the stock temp for the 14 which is a 207. So I'd opt for the later temp rating as 207 just seems too high to me.
Race Director
Joined: Apr 2014
Posts: 10,405
Likes: 1,707
From: North Texas
IMHO, if you are at 220* just cruising down the highway, you already have some sort of problem before it goes to 260*. If the temp reading is legit, then you probably have air in the system or a thermostat problem. My guess is either a bad temp sensor or a bad thermostat, although taking a shot at burping the system would be a good idea as well.