C7 Tech/Performance Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Thermostat stuck open?

Thread Tools
 
Search this Thread
 
Old Apr 10, 2026 | 03:01 PM
  #1  
IAIA's Avatar
IAIA
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Default 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.
Reply
Old Apr 10, 2026 | 03:35 PM
  #2  
kodpkd's Avatar
kodpkd
Le Mans Master
Active Streak: 30 Days
Community Builder
Community Influencer
Top Answer: 1
 
Joined: Jun 2019
Posts: 5,515
Likes: 2,205
From: Loveland
Default

Easy Peasy. Just make sure you get the correct temp spec. What car do you have?
Reply
Old Apr 10, 2026 | 05:45 PM
  #3  
DrivesWithTwoFeet's Avatar
DrivesWithTwoFeet
Melting Slicks
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Aug 2018
Posts: 2,016
Likes: 1,593
From: Clermont, Florida
Default

Classic bad thermostat symptoms. Rock Auto sells the whole housing at a good price.
Reply
Old Apr 10, 2026 | 06:48 PM
  #4  
IAIA's Avatar
IAIA
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Default

Originally Posted by kodpkd
Easy Peasy. Just make sure you get the correct temp spec. What car do you have?
2017 C7 Grand Sport

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.
Reply
Old Apr 10, 2026 | 08:59 PM
  #5  
M61A1MECH's Avatar
M61A1MECH
Burning Brakes
Veteran: Air Force
Active Streak: 90 Days
Active Streak: 120 Days
Liked
 
Joined: Jul 2021
Posts: 824
Likes: 471
From: Edgewater, FL
2024 C7 of the Year Finalist - Unmodified
Default

Originally Posted by IAIA
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.
When I replaced mine a few months ago I used went to Rockauto, they hade the best price, It is pretty simple, here is a link to the thread I started when I needed to replace mine, lots of good info and pictures.
https://www.corvetteforum.com/forums...s-done-it.html
Reply
Old Apr 10, 2026 | 08:59 PM
  #6  
CorvetteMike2024's Avatar
CorvetteMike2024
Corvette Enthusiast
Supporting Lifetime Gold
15 Year Member
 
Joined: Oct 2007
Posts: 6,800
Likes: 2,724
From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
Default

Originally Posted by IAIA
2017 C7 Grand Sport

Should I care whether it's GM OEM or aftermarket? (Motorad, Aisin, etc.) The price difference doesn't seem to be that significant.
OEM is your best choice. Best place to buy, Rock Auto.
Reply
Old Apr 11, 2026 | 07:13 AM
  #7  
Tinkertech's Avatar
Tinkertech
Melting Slicks
All Eyes On Me
Top Answer: 1
Top Answer: 3
Top Answer: 5
 
Joined: Feb 2018
Posts: 2,198
Likes: 1,057
From: North Texas
Default

Always OEM!
Reply
Old Apr 22, 2026 | 04:26 PM
  #8  
IAIA's Avatar
IAIA
Thread Starter
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2006
Posts: 2,308
Likes: 104
From: Orange County California
Default

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.

Last edited by IAIA; Apr 22, 2026 at 08:03 PM.
Reply

Get notified of new replies

To Thermostat stuck open?

Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

 Michael S. Palmer
story-1

5 Best & 5 Worst Corvette Daily Drivers

 Joe Kucinski
story-2

The Headlights of Every Corvette Generation Explained

 Joe Kucinski
story-3

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-4

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-5

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-6

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-7

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-8

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-9

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei




All times are GMT -4. The time now is 03:32 AM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-7
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-8
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-9
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE