Thermostat remove and replace, who has done it?
Thread Starter
Burning Brakes
Joined: Jul 2021
Posts: 824
Likes: 471
From: Edgewater, FL
2024 C7 of the Year Finalist - Unmodified
@96GS#007 has great pictures there and that should help.
I replaced the assembly with the thermostat. When you're ready to pull the assembly from the radiator hose, have the hose pointing up and be ready to push the new one in right after you remove the old one. I likely wouldn't have lost any coolant if I had done that.
I replaced the assembly with the thermostat. When you're ready to pull the assembly from the radiator hose, have the hose pointing up and be ready to push the new one in right after you remove the old one. I likely wouldn't have lost any coolant if I had done that.
Instructor
Joined: Jun 2016
Posts: 192
Likes: 90
From: Cary NC
I just did mine over the weekend. Do the whole housing and use the 193 degree thermostat. I lost about a pint of fluid mostly from the upper large hose you unhook. Like others have said, I put a big towel underneath the upper hose and it caught it all. I was thinking of zip tying a plastic bag on the hoses, but decided to just got for it. I had an estimate of 650 labor only charge. For that amount I was like no way, I will do it.
it’s a #30 torx head bolt. I bought the #30 socket at Home Depot and used my cordless socket wrench. Followed how they did it in the YouTube videos.
honestly I was done in 20 minutes, one of the easiest repairs out there. Don’t let the fact it’s a corvette scare you away, they’re not fragile, you won’t break it. Just get a good torx #30 socket and a 4-5 inch extension. Make sure you get the torx head snuggled onto the bolt and put pressure on it so the bit doesn’t walk and round the bolt opening.
seriously though it’s such an easy job and when you’re done you will be proud that did it yourself and you can take the 600-800 dollars and put it towards headers, an intake, or maybe even take your significant other on a great night out with the money. You can do it, it’s not hard at all.
it’s a #30 torx head bolt. I bought the #30 socket at Home Depot and used my cordless socket wrench. Followed how they did it in the YouTube videos.
honestly I was done in 20 minutes, one of the easiest repairs out there. Don’t let the fact it’s a corvette scare you away, they’re not fragile, you won’t break it. Just get a good torx #30 socket and a 4-5 inch extension. Make sure you get the torx head snuggled onto the bolt and put pressure on it so the bit doesn’t walk and round the bolt opening.
seriously though it’s such an easy job and when you’re done you will be proud that did it yourself and you can take the 600-800 dollars and put it towards headers, an intake, or maybe even take your significant other on a great night out with the money. You can do it, it’s not hard at all.
Melting Slicks
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
FYI: if you end up with trapped air in the system you could end up with a warped head and blown head gasket.
Been there, done that.
Thats why any time I open the cooling system I always pull a vacuum to make sure there is no air trapped anywhere. It's also less messy than using towels. If the coolant has any time on it, I'm replacing all of it anyway.
Note: most large shops have a machine that does all this automatically, I don't so I just use the stand-alone compressor operated vacuum devices.
Been there, done that.
Thats why any time I open the cooling system I always pull a vacuum to make sure there is no air trapped anywhere. It's also less messy than using towels. If the coolant has any time on it, I'm replacing all of it anyway.
Note: most large shops have a machine that does all this automatically, I don't so I just use the stand-alone compressor operated vacuum devices.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
FYI: if you end up with trapped air in the system you could end up with a warped head and blown head gasket.
Been there, done that.
Thats why any time I open the cooling system I always pull a vacuum to make sure there is no air trapped anywhere. It's also less messy than using towels. If the coolant has any time on it, I'm replacing all of it anyway.
Note: most large shops have a machine that does all this automatically, I don't so I just use the stand-alone compressor operated vacuum devices.
Been there, done that.
Thats why any time I open the cooling system I always pull a vacuum to make sure there is no air trapped anywhere. It's also less messy than using towels. If the coolant has any time on it, I'm replacing all of it anyway.
Note: most large shops have a machine that does all this automatically, I don't so I just use the stand-alone compressor operated vacuum devices.
In fact, if you tilted the radiator hose down to “drain it”, you still couldn’t get enough coolant out for that to happen. Lastly, just based on flow and location the system will burp air If someone manages to get air in there.
Never say never when humans are involved but it would take mechanical incompetence to a new level.
Last edited by 96GS#007; Aug 28, 2025 at 06:25 PM.
Melting Slicks
Joined: Dec 2004
Posts: 2,541
Likes: 773
Ron,
Can you not see my profile, I am pretty sure it is complete from what I can see.
Thanks, I have watched a few You Tube videos, but the do not touch on all the questions I have. One guy says he had minimal spillage another said he lost a lot of fluid from both side of the thermostat. I was concerned when I saw the torx heads on those bolts.
Steve K
Can you not see my profile, I am pretty sure it is complete from what I can see.
Thanks, I have watched a few You Tube videos, but the do not touch on all the questions I have. One guy says he had minimal spillage another said he lost a lot of fluid from both side of the thermostat. I was concerned when I saw the torx heads on those bolts.
Steve K
Thread Starter
Burning Brakes
Joined: Jul 2021
Posts: 824
Likes: 471
From: Edgewater, FL
2024 C7 of the Year Finalist - Unmodified
Melting Slicks
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
"Utterly incompetent" not really.
It does not take a lot of air trapped in the head to create a 'hot' spot to create an overheating condition in this area which can lead to a lot of damage. The system needs to be 100% filled, no air at all, for it to work properly. Trapped air is the Debel. Cars that are designed to self-burp sometimes don't. Ask me how I know.
Why take a chance? I always did until trapped air overheated and warped the head then blew the head gasket. $$$. I learned my lesson well and now always use a vacuum device.
Almost all competent techs always use a vacuum device or machine when the system is opened, they don't like come backs on their dime. (Actually, big time and $$$). Most large shops have an automatic coolant exchange machine that does it all at the push of a button.
When GM assembles a car at the factory, do you really think they have some guy pouring in coolant thru a funnel and then sit around and try to burp a cooling system? No, it's automatically vacuumed filled by a machine in seconds.
Roll the dice, YMMV.
It does not take a lot of air trapped in the head to create a 'hot' spot to create an overheating condition in this area which can lead to a lot of damage. The system needs to be 100% filled, no air at all, for it to work properly. Trapped air is the Debel. Cars that are designed to self-burp sometimes don't. Ask me how I know.
Why take a chance? I always did until trapped air overheated and warped the head then blew the head gasket. $$$. I learned my lesson well and now always use a vacuum device.
Almost all competent techs always use a vacuum device or machine when the system is opened, they don't like come backs on their dime. (Actually, big time and $$$). Most large shops have an automatic coolant exchange machine that does it all at the push of a button.
When GM assembles a car at the factory, do you really think they have some guy pouring in coolant thru a funnel and then sit around and try to burp a cooling system? No, it's automatically vacuumed filled by a machine in seconds.
Roll the dice, YMMV.
Last edited by Tinkertech; Aug 29, 2025 at 07:56 AM.
Le Mans Master
Joined: Jun 2019
Posts: 5,514
Likes: 2,204
From: Loveland
This trapped air thing, I think is an old wives tale. I have drained many radiators. Didn't use any special tool to suck or pressurize the system. Never has been an issue. Just don't be dumb about it.
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Melting Slicks
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
Depends on the configuration of the engine compartment.
If the radiator is below the top of the heads, you can easily trap air.
I already explained how trapped air damages engines.
To be safe, always use a vacuum device.
Peace
If the radiator is below the top of the heads, you can easily trap air.
I already explained how trapped air damages engines.
To be safe, always use a vacuum device.
Peace
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
"Utterly incompetent" not really.
It does not take a lot of air trapped in the head to create a 'hot' spot to create an overheating condition in this area which can lead to a lot of damage. The system needs to be 100% filled, no air at all, for it to work properly. Trapped air is the Debel. Cars that are designed to self-burp sometimes don't. Ask me how I know.
Why take a chance? I always did until trapped air overheated and warped the head then blew the head gasket. $$$. I learned my lesson well and now always use a vacuum device.
Almost all competent techs always use a vacuum device or machine when the system is opened, they don't like come backs on their dime. (Actually, big time and $$$). Most large shops have an automatic coolant exchange machine that does it all at the push of a button.
When GM assembles a car at the factory, do you really think they have some guy pouring in coolant thru a funnel and then sit around and try to burp a cooling system? No, it's automatically vacuumed filled by a machine in seconds.
Roll the dice, YMMV.
It does not take a lot of air trapped in the head to create a 'hot' spot to create an overheating condition in this area which can lead to a lot of damage. The system needs to be 100% filled, no air at all, for it to work properly. Trapped air is the Debel. Cars that are designed to self-burp sometimes don't. Ask me how I know.
Why take a chance? I always did until trapped air overheated and warped the head then blew the head gasket. $$$. I learned my lesson well and now always use a vacuum device.
Almost all competent techs always use a vacuum device or machine when the system is opened, they don't like come backs on their dime. (Actually, big time and $$$). Most large shops have an automatic coolant exchange machine that does it all at the push of a button.
When GM assembles a car at the factory, do you really think they have some guy pouring in coolant thru a funnel and then sit around and try to burp a cooling system? No, it's automatically vacuumed filled by a machine in seconds.
Roll the dice, YMMV.
I’m quite aware of how multi 100s of millions of dollars factories work, as well as fully equipped shops.
A DIY C7 thermostat change is damn near as easy as putting gas in the car so blowing it up is incompetence. Not hard to check gauges, touch the hoses, or use a cheap IR tester (if available) to do a quick check.
On other cars, a vacuum is needed. Many newer BMWs fall into that camp as an example. Some older cars are a PIA without a vacuum. The Z06 intercooler circuit needs a vacuum.
For the topic at hand….C7 Corvette LT1….pulling a vacuum is a nicety and implying someone is on the ragged edge of grenading their engine via the loss of a few ounces of fluid is disingenuous.
Melting Slicks
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
"This is called fear mongering"
No, it's not. 99 out of 100 times you can just pour and go but that one-time when things go wrong, you'll be here asking for advice.
I've been down this road, have you?
Even the service manual shows both ways but has a lot more detail on the vacuum method. If it was not necessary, why would they even put it in the service manual?
As your method of "check gauges, touch the hoses, or use a cheap IR tester" won't tell you if you have a trapped air pocket which almost always occurs in the heads. then it will be too late, damage done.
Back yard shade tree mechanic methods died out years ago. Engines back then were all cast iron, which were not suspect to warping when overheated. Trapped air was rare back then, because engines were almost always lower than the radiator, i.e.: self-burping. Today all engines are aluminum and not always lower than the radiator. Perfect scenario for a trapped air situation.
Go down to any good shop or dealership and see for yourself, almost all good techs have and use a vacuum device. Like I have pointed out, there are reasons for using them. Do they always use them? Probably not, flat rate and all, $$$.
Your correct, you won't grenade your engine immediately, but after a few weeks if indeed you ended up with trapped air, your engine will start to ping, hydrocarbons will show up in the engine coolant, coolant can end up in your oil and bubbles will start to appear in your overflow tank. At this point, it's too late. I've lived it.
I'm not being "disingenuous" just relating from years of experience trying to help others from making the same mistakes as I did before I learned otherwise Yes, it takes more time and the expense of the vacuum equipment but in the long run it pays off.
As C5 has always pointed out numerous times, too many people try to diagnosis their cars with a cheap code reader and a $7 HF DVM. Things just really don't work that way anymore. Basically, he's saying you need a lot of expensive equipment and a whole lot of knowledge to diagnose modern cars correctly. Thus, take it to a good diagnostician.
Don't know what else I could add to help but....
I wish you well.
No, it's not. 99 out of 100 times you can just pour and go but that one-time when things go wrong, you'll be here asking for advice.
I've been down this road, have you?
Even the service manual shows both ways but has a lot more detail on the vacuum method. If it was not necessary, why would they even put it in the service manual?
As your method of "check gauges, touch the hoses, or use a cheap IR tester" won't tell you if you have a trapped air pocket which almost always occurs in the heads. then it will be too late, damage done.
Back yard shade tree mechanic methods died out years ago. Engines back then were all cast iron, which were not suspect to warping when overheated. Trapped air was rare back then, because engines were almost always lower than the radiator, i.e.: self-burping. Today all engines are aluminum and not always lower than the radiator. Perfect scenario for a trapped air situation.
Go down to any good shop or dealership and see for yourself, almost all good techs have and use a vacuum device. Like I have pointed out, there are reasons for using them. Do they always use them? Probably not, flat rate and all, $$$.
Your correct, you won't grenade your engine immediately, but after a few weeks if indeed you ended up with trapped air, your engine will start to ping, hydrocarbons will show up in the engine coolant, coolant can end up in your oil and bubbles will start to appear in your overflow tank. At this point, it's too late. I've lived it.
I'm not being "disingenuous" just relating from years of experience trying to help others from making the same mistakes as I did before I learned otherwise Yes, it takes more time and the expense of the vacuum equipment but in the long run it pays off.
As C5 has always pointed out numerous times, too many people try to diagnosis their cars with a cheap code reader and a $7 HF DVM. Things just really don't work that way anymore. Basically, he's saying you need a lot of expensive equipment and a whole lot of knowledge to diagnose modern cars correctly. Thus, take it to a good diagnostician.
Don't know what else I could add to help but....
I wish you well.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
"This is called fear mongering"
No, it's not. 99 out of 100 times you can just pour and go but that one-time when things go wrong, you'll be here asking for advice.
I've been down this road, have you?
Even the service manual shows both ways but has a lot more detail on the vacuum method. If it was not necessary, why would they even put it in the service manual?
As your method of "check gauges, touch the hoses, or use a cheap IR tester" won't tell you if you have a trapped air pocket which almost always occurs in the heads. then it will be too late, damage done.
Back yard shade tree mechanic methods died out years ago. Engines back then were all cast iron, which were not suspect to warping when overheated. Trapped air was rare back then, because engines were almost always lower than the radiator, i.e.: self-burping. Today all engines are aluminum and not always lower than the radiator. Perfect scenario for a trapped air situation.
Go down to any good shop or dealership and see for yourself, almost all good techs have and use a vacuum device. Like I have pointed out, there are reasons for using them. Do they always use them? Probably not, flat rate and all, $$$.
Your correct, you won't grenade your engine immediately, but after a few weeks if indeed you ended up with trapped air, your engine will start to ping, hydrocarbons will show up in the engine coolant, coolant can end up in your oil and bubbles will start to appear in your overflow tank. At this point, it's too late. I've lived it.
I'm not being "disingenuous" just relating from years of experience trying to help others from making the same mistakes as I did before I learned otherwise Yes, it takes more time and the expense of the vacuum equipment but in the long run it pays off.
As C5 has always pointed out numerous times, too many people try to diagnosis their cars with a cheap code reader and a $7 HF DVM. Things just really don't work that way anymore. Basically, he's saying you need a lot of expensive equipment and a whole lot of knowledge to diagnose modern cars correctly. Thus, take it to a good diagnostician.
Don't know what else I could add to help but....
I wish you well.
No, it's not. 99 out of 100 times you can just pour and go but that one-time when things go wrong, you'll be here asking for advice.
I've been down this road, have you?
Even the service manual shows both ways but has a lot more detail on the vacuum method. If it was not necessary, why would they even put it in the service manual?
As your method of "check gauges, touch the hoses, or use a cheap IR tester" won't tell you if you have a trapped air pocket which almost always occurs in the heads. then it will be too late, damage done.
Back yard shade tree mechanic methods died out years ago. Engines back then were all cast iron, which were not suspect to warping when overheated. Trapped air was rare back then, because engines were almost always lower than the radiator, i.e.: self-burping. Today all engines are aluminum and not always lower than the radiator. Perfect scenario for a trapped air situation.
Go down to any good shop or dealership and see for yourself, almost all good techs have and use a vacuum device. Like I have pointed out, there are reasons for using them. Do they always use them? Probably not, flat rate and all, $$$.
Your correct, you won't grenade your engine immediately, but after a few weeks if indeed you ended up with trapped air, your engine will start to ping, hydrocarbons will show up in the engine coolant, coolant can end up in your oil and bubbles will start to appear in your overflow tank. At this point, it's too late. I've lived it.
I'm not being "disingenuous" just relating from years of experience trying to help others from making the same mistakes as I did before I learned otherwise Yes, it takes more time and the expense of the vacuum equipment but in the long run it pays off.
As C5 has always pointed out numerous times, too many people try to diagnosis their cars with a cheap code reader and a $7 HF DVM. Things just really don't work that way anymore. Basically, he's saying you need a lot of expensive equipment and a whole lot of knowledge to diagnose modern cars correctly. Thus, take it to a good diagnostician.
Don't know what else I could add to help but....
I wish you well.
For liability reasons, I'm surprised GM or most other manufacturers sell basic maintenance parts to anyone other than dealers. They need to go the full McLaren route but instead of significant repairs like McLaren, for any repairs you'll need to ship the car back to them. A friend had to do that with his McLaren btw....all the way back to the UK.
Good luck. If you'll excuse me, I need to go look for my tinfoil hat. After that I'm going to search the usual sites for all the C7s with blown engines due to thermostat changes. I should be able to pick them up pretty cheaply so I can install a new engine and flip them
Le Mans Master
Joined: Jun 2019
Posts: 5,514
Likes: 2,204
From: Loveland
I watched the videos on suction bleeding. So, take a glass jar, put 25 psi suction on it, stick the mouth in water, it will not be full when it sucks water in. Even when vacuum filling your radiator system, you will still need to burp the system. I would also worry about collapsing a metal radiator with 25 psi suction on it. I do agree, you do need to know what you are doing, but this also applies to even changing spark plugs and air filters.
Tech Contributor
Joined: Jan 2015
Posts: 5,693
Likes: 1,451
I watched the videos on suction bleeding. So, take a glass jar, put 25 psi suction on it, stick the mouth in water, it will not be full when it sucks water in. Even when vacuum filling your radiator system, you will still need to burp the system. I would also worry about collapsing a metal radiator with 25 psi suction on it. I do agree, you do need to know what you are doing, but this also applies to even changing spark plugs and air filters.
Thread Starter
Burning Brakes
Joined: Jul 2021
Posts: 824
Likes: 471
From: Edgewater, FL
2024 C7 of the Year Finalist - Unmodified
I watched the videos on suction bleeding. So, take a glass jar, put 25 psi suction on it, stick the mouth in water, it will not be full when it sucks water in. Even when vacuum filling your radiator system, you will still need to burp the system. I would also worry about collapsing a metal radiator with 25 psi suction on it. I do agree, you do need to know what you are doing, but this also applies to even changing spark plugs and air filters.
Just for reference, here is link.
https://www.google.com/search?q=what...hrome&ie=UTF-8
Melting Slicks
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
Let's take a minute and talk about the subject of vacuum.
Vacuums higher than ~29" of mercury are usually measured in Torr's.
Medium vacuums start at ~ 10 to the - 1.5 torr.
Hard vacuums start at ~ 10 to the -3 torr, you'll need a high-quality laboratory roughing pump (vacuum pump) in series with a turbo or cryogenic pump. Extreme high vacuums >10 to the -6 torr will require additional specialized equipment.
On our cars:
Our cars cooling system only a requires a vacuum of ~25 - 27" of mercury to pull a good vacuum which can be achieved with a compressor operated venturi vacuum pump coolant refilling system. This will remove 99% of the air in a good, sealed car's coolant system. This is what you want. Will it remove every tiny bubble the size of a pencil dot, no. But it won't leave a bubble the size of a golf ball either. This is the end result you're after.
The above-mentioned equipment works very well; I've used all of them for many years with excellent results in R&D labs and at home.
You can debate all you want but you just can't beat the physics. It's just how this equipment works.
Peace.
Vacuums higher than ~29" of mercury are usually measured in Torr's.
Medium vacuums start at ~ 10 to the - 1.5 torr.
Hard vacuums start at ~ 10 to the -3 torr, you'll need a high-quality laboratory roughing pump (vacuum pump) in series with a turbo or cryogenic pump. Extreme high vacuums >10 to the -6 torr will require additional specialized equipment.
On our cars:
Our cars cooling system only a requires a vacuum of ~25 - 27" of mercury to pull a good vacuum which can be achieved with a compressor operated venturi vacuum pump coolant refilling system. This will remove 99% of the air in a good, sealed car's coolant system. This is what you want. Will it remove every tiny bubble the size of a pencil dot, no. But it won't leave a bubble the size of a golf ball either. This is the end result you're after.
The above-mentioned equipment works very well; I've used all of them for many years with excellent results in R&D labs and at home.
You can debate all you want but you just can't beat the physics. It's just how this equipment works.
Peace.
Last edited by Tinkertech; Sep 1, 2025 at 11:19 AM. Reason: edited for punctuation
Advanced
Joined: May 2019
Posts: 96
Likes: 61
From: Harrison TN
So I don't have to do it in a couple of years? I'm already dumping much of the coolant in the radiator. Might as well flush it and call it good for 5 years. I have never done a C7 thermostat but any other car that I have done one on, I never cared to try the job with just mopping up the little bit of coolant. I usually lower the level quite a bit first. Less messy, at least for me, to lower the levels a lot or drain the radiator into a pan than to try get a thermostat in with most of the fluid in the system.
Took my time no mess and was done in an hour. Ordered whole unit from Rock Auto and believe was not over $100 about a year ago.
Team Owner
Joined: Jul 2004
Posts: 28,501
Likes: 3,302
From: Hartford WI
I'd buy it from GM and if needed, warranty from them. Warranty was a PITA and my next day became 3 day with no recourse. Mechanic was pissed with the car on the rack and they didn't refund my next day shipping.
