Overheating to 260 degrees
Thread Starter
Instructor
Joined: Aug 2013
Posts: 172
Likes: 0
Overheating to 260 degrees
I'm looking for advice here, please.
C7 Z51
Radiator gauge hits 260 and drops back to 220 ten seconds later. I replaced the thermostat and it didn't help. I would like to ask if anyone has been through this before and if they identified the root cause?
Sorry, I should also add that this happens when I'm cruising at 60MPH and 65 degrees outside.
C7 Z51
Radiator gauge hits 260 and drops back to 220 ten seconds later. I replaced the thermostat and it didn't help. I would like to ask if anyone has been through this before and if they identified the root cause?
Sorry, I should also add that this happens when I'm cruising at 60MPH and 65 degrees outside.
Last edited by C7Z51_2014; Mar 16, 2015 at 01:16 PM.
Safety Car
Joined: Aug 2012
Posts: 3,960
Likes: 1,106
Such rapid changes are generally from a sensor or wiring issue. Do you have a reader you can plug into the OBDII port to see the reported sensor value. The IP gauges are stepper motors and the display is probably damped. If you see huge instant changes in sensor reported value then the problem is almost certainly a sensor.
To actually get a 40 degree change in 10 seconds (I assume the rise is equally fast) would require temporary blockage/stoppage of coolant flow or a gas bubble at the sensor from HG or similar issues; either is a very low probability.
Is the car stock? If so it needs to go to the dealer for a check and to get this noted while in warranty.
To actually get a 40 degree change in 10 seconds (I assume the rise is equally fast) would require temporary blockage/stoppage of coolant flow or a gas bubble at the sensor from HG or similar issues; either is a very low probability.
Is the car stock? If so it needs to go to the dealer for a check and to get this noted while in warranty.
Racer
Joined: Jul 2014
Posts: 324
Likes: 7
From: Washington
I'm looking for advice here, please.
C7 Z51
Radiator gauge hits 260 and drops back to 220 ten seconds later. I replaced the thermostat and it didn't help. I would like to ask if anyone has been through this before and if they identified the root cause?
Sorry, I should also add that this happens when I'm cruising at 60MPH and 65 degrees outside.
C7 Z51
Radiator gauge hits 260 and drops back to 220 ten seconds later. I replaced the thermostat and it didn't help. I would like to ask if anyone has been through this before and if they identified the root cause?
Sorry, I should also add that this happens when I'm cruising at 60MPH and 65 degrees outside.
Thread Starter
Instructor
Joined: Aug 2013
Posts: 172
Likes: 0
Such rapid changes are generally from a sensor or wiring issue. Do you have a reader you can plug into the OBDII port to see the reported sensor value. The IP gauges are stepper motors and the display is probably damped. If you see huge instant changes in sensor reported value then the problem is almost certainly a sensor.
To actually get a 40 degree change in 10 seconds (I assume the rise is equally fast) would require temporary blockage/stoppage of coolant flow or a gas bubble at the sensor from HG or similar issues; either is a very low probability.
Is the car stock? If so it needs to go to the dealer for a check and to get this noted while in warranty.
To actually get a 40 degree change in 10 seconds (I assume the rise is equally fast) would require temporary blockage/stoppage of coolant flow or a gas bubble at the sensor from HG or similar issues; either is a very low probability.
Is the car stock? If so it needs to go to the dealer for a check and to get this noted while in warranty.
Thank you for the reply.
Dealer suggested thermostat first before trying to hunt down a sensor. I like the dealer and find them very helpful. I'm taking it in next week but thought I would ask this group if anyone has already been down this road.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Thread Starter
Instructor
Joined: Aug 2013
Posts: 172
Likes: 0
Was thinking about the head gasket but there's no fluid anywhere and oil looks good. Also, there's no overheating on any of the other readouts.
Any other thoughts on what this could be are appreciated.
Team Owner
Joined: Apr 2008
Posts: 22,356
Likes: 1,683
From: South Carolina
Your is probably a sensor or something else simple...good luck
Thread Starter
Instructor
Joined: Aug 2013
Posts: 172
Likes: 0
Although I doubt it's likely I have owned a car one where the head gasket went bad and no leaks or noise...The only "tell' was bubbles in the coolant and it would stop after it warmed up...It did have a lot of condensation out the exhaust for a short period after a cold start but otherwise no signs of any problems except the rapid "hot then normal appearance of the gauge...The leak was small and allowed combustion into the coolant...
Your is probably a sensor or something else simple...good luck
Your is probably a sensor or something else simple...good luck
Safety Car
Joined: Aug 2012
Posts: 3,960
Likes: 1,106
The dealer tech can easily test for exhaust gas contamination of the coolant but I still believe a sensor issue is much more likely than a HG issue. A defective coolant hose that collapses under suction is another very small possibility, not likely in a low mile vehicle however.
I recall reading about one new vehicle that had a piece of cooling system debris from a hose that was just large enough to get stuck from time to time in the thermostat passage, when it stuck the temperature would spike causing the thermostat to fully open allowing it to pass through and intermittently repeat. But the dealer should check for all the high likelihood stuff before looking for the "anything is possible" stuff in the tail of the probability curve.
I recall reading about one new vehicle that had a piece of cooling system debris from a hose that was just large enough to get stuck from time to time in the thermostat passage, when it stuck the temperature would spike causing the thermostat to fully open allowing it to pass through and intermittently repeat. But the dealer should check for all the high likelihood stuff before looking for the "anything is possible" stuff in the tail of the probability curve.