C8 Overheated
Thread Starter
Heel & Toe
Joined: Jun 2020
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C8 Overheated
2020 C8 with 2800 miles overheated to 240 with no lights or sensors indicating coolant loss. Dealer found leaking head gasket as of now but working to find other potential damage to the engine. Is it possible that the performance of the car is permanently affected? How likely is there damage to engine that may manifest itself in the future? What kinds of test and analysis should be done and should I be worried?
Pro
Joined: Jan 2021
Posts: 649
Likes: 576
From: South Florida
2020 C8 with 2800 miles overheated to 240 with no lights or sensors indicating coolant loss. Dealer found leaking head gasket as of now but working to find other potential damage to the engine. Is it possible that the performance of the car is permanently affected? How likely is there damage to engine that may manifest itself in the future? What kinds of test and analysis should be done and should I be worried?
You could do a compression test.
But opening the engine up would probably be best, and that’s what I imagine the service dept will do.
What’s Next
Joined: Dec 2020
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From: Reality
Getting to 240 isn't harmful but it shows an issue under normal driving. So I wouldn't call it overheated at that point. But it's still a good idea to inspect for other signs while changing out head gasket. I assume you were just driving casual when it came about. Did you ever smell anything leading up to this?
Thread Starter
Heel & Toe
Joined: Jun 2020
Posts: 23
Likes: 11
Getting to 240 isn't harmful but it shows an issue under normal driving. So I wouldn't call it overheated at that point. But it's still a good idea to inspect for other signs while changing out head gasket. I assume you were just driving casual when it came about. Did you ever smell anything leading up to this?
Last edited by Black_Pearlzzz; Aug 24, 2021 at 11:04 PM.
Burning Brakes
Joined: Sep 2019
Posts: 1,089
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From: Orange County, CA
Bad overheating can warp heads on some cars. Not sure about the LT2. The shop will check the deck and head mating surfaces for flatness when they put head gaskets on it.
Worst case head surface would need to be resurfaced. Either way the rest of the motor will be fine.
Worst case head surface would need to be resurfaced. Either way the rest of the motor will be fine.
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Race Director
Joined: Dec 2006
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From: Fort Worth, Texas
It shouldn’t get that hot on the street, but 240* shouldn’t be an issue as I hit that regularly on track in my C6 before shutting it down. What’s the over temp warning at on a C8?
Race Director
Joined: Mar 2007
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The leaking head gasket would be of considerable concern to me. How was it found? Water leaking out? Or .... I have a test kit that tests for combustion products leaking into the cooling system that I use on my older cars. This is usually due to a head gasket problem, but can be due to other internal issues, like a crack in something. This type of leakage can cause overheating as the hot gasses escape into the cooling system. Regardless, did the overheating cause the leak, or was there a leak that caused the overheating. I any case, you will have to rely on the service department to tell you the extent of the damage. And yes, a compression check should be one of the tests.
Melting Slicks
Joined: Jun 2012
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From: Thomas Texas
Depends on how bad and where the coolant went. Coolant in the crank case is bad as it dilutes the oil and could wipe out the bearings resulting in a new engine. If the coolant leaked outside the block and the system became low on coolant resulting in 240° temp, that's not so bad. The question then is why did the head gasket fail? Improper installation? Head bolts not torqued to spec? Block or head warped and out of flatness spec? Bad head gasket? The service tech should be able provide some information after the head is removed or the engine pulled.
Over the years, lots of engines had head gasket leaks and the repair was simply replace the head gasket. Don't know at this point, but don't simply assume the worse.
Over the years, lots of engines had head gasket leaks and the repair was simply replace the head gasket. Don't know at this point, but don't simply assume the worse.
Race Director
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From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
Has the car had any other work done recently? We've had a couple cars that had a cooling fan, radiator or similar part replaced at another dealer and then come in for over heating a few hundred miles later. The cooling system is a bitch to bleed correctly and both cars had air trapped in the system after their previous repairs. Both cars registered coolant temps in the 250+ range before getting towed in. We bled the cooling system, confirmed the coolant level and sent them on with no other issues.
It's even possible your car had an air pocket from the factory and the coolant temp sensor was reading that air pocket.
It's even possible your car had an air pocket from the factory and the coolant temp sensor was reading that air pocket.
Pro
Joined: Jul 2019
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Has the car had any other work done recently? We've had a couple cars that had a cooling fan, radiator or similar part replaced at another dealer and then come in for over heating a few hundred miles later. The cooling system is a bitch to bleed correctly and both cars had air trapped in the system after their previous repairs. Both cars registered coolant temps in the 250+ range before getting towed in. We bled the cooling system, confirmed the coolant level and sent them on with no other issues.
It's even possible your car had an air pocket from the factory and the coolant temp sensor was reading that air pocket.
It's even possible your car had an air pocket from the factory and the coolant temp sensor was reading that air pocket.
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Melting Slicks
Joined: Jun 2012
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From: Thomas Texas
During the event they COTA back in October it was also 100° and I never saw over 225 either and I have the screens installed. I know at Spring Mountain they don’t use screens
Race Director
Joined: Dec 2006
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From: Fort Worth, Texas
That’s impressive, just curious how hard you were pushing it i.e. what kind of lap times you were turning?
Melting Slicks
Joined: Jun 2012
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From: Thomas Texas
my lap times weren’t that great. Full throttle is on the front and back straights. So most of the
time you’re in the corners so not full throttle.
Melting Slicks
Joined: Oct 2004
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From: Nevada
Getting to 240 isn't harmful but it shows an issue under normal driving. So I wouldn't call it overheated at that point. But it's still a good idea to inspect for other signs while changing out head gasket. I assume you were just driving casual when it came about. Did you ever smell anything leading up to this?