Thermostat stuck open?
Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Thermostat stuck open?
My GS has been showing the "yellow" on the tach, for a while. Comes and goes. Even when fully warmed up and esp. on the highway (unless I'm revving high). The temp is usually ~170, even when the yellow disappears. I think it's supposed to be 180-220. So, seems the thermostat is stuck open. I've replaced them on other cars, but never on my Corvettes. Advice? Easily done? Thanks.
Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Should I care whether it's GM OEM or aftermarket? (Motorad, Aisin, etc.) The price difference doesn't seem to be that significant.
Last edited by IAIA; Apr 10, 2026 at 07:00 PM.
Burning Brakes
Joined: Jul 2021
Posts: 816
Likes: 460
From: Edgewater, FL
2024 C7 of the Year Finalist - Unmodified
My GS has been showing the "yellow" on the tach, for a while. Comes and goes. Even when fully warmed up and esp. on the highway (unless I'm revving high). The temp is usually ~170, even when the yellow disappears. I think it's supposed to be 180-220. So, seems the thermostat is stuck open. I've replaced them on other cars, but never on my Corvettes. Advice? Easily done? Thanks.
https://www.corvetteforum.com/forums...s-done-it.html
Corvette Enthusiast
Joined: Oct 2007
Posts: 6,790
Likes: 2,697
From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,481
Likes: 2,663
From: Troy & Dearborn, Michigan
My GS has been showing the "yellow" on the tach, for a while. Comes and goes. Even when fully warmed up and esp. on the highway (unless I'm revving high). The temp is usually ~170, even when the yellow disappears. I think it's supposed to be 180-220. So, seems the thermostat is stuck open. I've replaced them on other cars, but never on my Corvettes. Advice? Easily done? Thanks.
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Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Since the "other" thread of late that included R/R of the thermostat, I can say here that I just finished replacing mine. As mentioned, easy-peezy. This forum has always rocked with the helpful tips and information. Couldn't have done it without y'all. Thanks.
UPDATE: took it for a test drive and pushed it to see how the temp would adjust. No yellow on the tach after about 2 minutes, and rock solid 195 degrees.
UPDATE: took it for a test drive and pushed it to see how the temp would adjust. No yellow on the tach after about 2 minutes, and rock solid 195 degrees.
Last edited by IAIA; Apr 22, 2026 at 08:03 PM.