Change in coolant temp?
Thread Starter
Racer
Joined: Sep 2011
Posts: 409
Likes: 91
Change in coolant temp?
Several months ago I installed ARH headers, a 160 t-stat and had the car dyno tuned. After that, the car would rarely see coolant temps above 190 in weather like today's and it would take a good while to get there. This past week, we experienced snowmaggedon 2021 in Texas with several days of temps well below freezing. I think the low was 5 degrees one day. So as things go in Texas, we are now back to beautiful weather with highs in the 70s. I've been driving the car for the past couple of days and noticed that it now regularly runs between 199 and 208 and gets there in just a short drive across town. Coolant tank is full, car is running great and the fan seems to be working properly.
Does anyone have any ideas about what may be going on? I know that 199 to 208 is not too hot. What concerns me is the change in behavior and the fact that the heat of the summer will be here soon.
Thanks
Does anyone have any ideas about what may be going on? I know that 199 to 208 is not too hot. What concerns me is the change in behavior and the fact that the heat of the summer will be here soon.
Thanks
Safety Car
Joined: Dec 2012
Posts: 3,841
Likes: 1,856
From: St. Louis Metro East IL
Minimum operating temp is set by the thermostat. In cold weather and low engine load the coolant temp is set by the thermostat. Obviously 160 is lower than the stock thermostat. The car will take longer to warm up and may never reach stock operating temps. If this is a problem, you may want to reconsider the 160 thermostat.
Max temp is set by cooling capacity and radiator fan tuning settings since the thermostat will be fully open. You should not see any difference in warm / hot temps or high load operation.
Ron
Max temp is set by cooling capacity and radiator fan tuning settings since the thermostat will be fully open. You should not see any difference in warm / hot temps or high load operation.
Ron
Thread Starter
Racer
Joined: Sep 2011
Posts: 409
Likes: 91
Minimum operating temp is set by the thermostat. In cold weather and low engine load the coolant temp is set by the thermostat. Obviously 160 is lower than the stock thermostat. The car will take longer to warm up and may never reach stock operating temps. If this is a problem, you may want to reconsider the 160 thermostat.
Max temp is set by cooling capacity and radiator fan tuning settings since the thermostat will be fully open. You should not see any difference in warm / hot temps or high load operation.
Ron
Max temp is set by cooling capacity and radiator fan tuning settings since the thermostat will be fully open. You should not see any difference in warm / hot temps or high load operation.
Ron
Safety Car
Joined: Dec 2012
Posts: 3,841
Likes: 1,856
From: St. Louis Metro East IL
If it is now running cooler it is possible that the thermostat sticks open or was damaged and can't fully close. A restricted / not able to full open thermostat would run warmer and a stuck closed thermostat would cause overheating.
Yeah, possible damage due to the cold could be possible or just a random failure.
Ron
Yeah, possible damage due to the cold could be possible or just a random failure.
Ron
Thread Starter
Racer
Joined: Sep 2011
Posts: 409
Likes: 91
If it is now running cooler it is possible that the thermostat sticks open or was damaged and can't fully close. A restricted / not able to full open thermostat would run warmer and a stuck closed thermostat would cause overheating.
Yeah, possible damage due to the cold could be possible or just a random failure.
Ron
Yeah, possible damage due to the cold could be possible or just a random failure.
Ron
Drifting
Joined: Jun 2013
Posts: 1,428
Likes: 478
From: Maryland, USA
trying running the heat on full hot for a bit, then turn on full cold a/c and see what the happens to the temps.
ensure nothing is blocking the radiator as well, check all coolant hoses to ensure none are collapsing.
it is happening at low speeds or highway? depending on which you indicate more issues on blockage vs. other stuff.
overall sounds like you might need to just keep an eye on it for the next few drive cycles to monitor the behavior.
I believe coolant nowadays last for well over 100k miles but if u needed to add some overtime depending on the mix you put in might need to be replaced with a better mixture perhaps?
ensure nothing is blocking the radiator as well, check all coolant hoses to ensure none are collapsing.
it is happening at low speeds or highway? depending on which you indicate more issues on blockage vs. other stuff.
overall sounds like you might need to just keep an eye on it for the next few drive cycles to monitor the behavior.
I believe coolant nowadays last for well over 100k miles but if u needed to add some overtime depending on the mix you put in might need to be replaced with a better mixture perhaps?
Last edited by mdformula350; Feb 25, 2021 at 06:31 AM.
Racer
Joined: Jun 2019
Posts: 386
Likes: 149
I'm guessing you have the dexcool mix in the car? i mean, not just water, correct? If so, I don't see how anything would freeze in there. With that said, 5*F is very cold, so if the coolant proportion is low relatively to water then you could potentially experience the freeze.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
Safety Car
Joined: Nov 2011
Posts: 3,714
Likes: 343
From: Norman OK
I'm guessing you have the dexcool mix in the car? i mean, not just water, correct? If so, I don't see how anything would freeze in there. With that said, 5*F is very cold, so if the coolant proportion is low relatively to water then you could potentially experience the freeze.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
It has been shows time again, a 160 t-stat will allow better timing control over the stock 194° t-stat. Just by changing the stat alone it can help reduce instances of detonation during the warmer months. I've had a 160° stat in my 2017 Camaro SS for over 3 years now, zero issues and zero condensation in the oil or inside of the oil fill cap or the catch can. Where the car would run in the 210° range stock it now runs in the 180°-190° range during even the hottest summer months.
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Racer
Joined: Jun 2019
Posts: 386
Likes: 149
It has been shows time again, a 160 t-stat will allow better timing control over the stock 194° t-stat. Just by changing the stat alone it can help reduce instances of detonation during the warmer months. I've had a 160° stat in my 2017 Camaro SS for over 3 years now, zero issues and zero condensation in the oil or inside of the oil fill cap or the catch can. Where the car would run in the 210° range stock it now runs in the 180°-190° range during even the hottest summer months.
Thread Starter
Racer
Joined: Sep 2011
Posts: 409
Likes: 91
I'm guessing you have the dexcool mix in the car? i mean, not just water, correct? If so, I don't see how anything would freeze in there. With that said, 5*F is very cold, so if the coolant proportion is low relatively to water then you could potentially experience the freeze.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
As long as there are no leaks, I would replace the thermostat and see what happens. Besides that, you may be looking at a damaged pump impeller.
Also, I don't understand why the 160*F at all. It doesn't increase the cooling capacity of the system at all. All it does is puts you at risk of not evaporating any water condensation in your oil reservoirs after a short drive.
Instructor
Joined: Nov 2015
Posts: 167
Likes: 54
From: Lumberton Texas
Just a little more info for you to gauge... My '16 z51 with OEM thermostat & untuned, was seeing a consistent 160-165* (engine coolant temp) last week when outside temps were well below 50*. Now that temps are back to 68-74* my car is regularly seeing 190-199* with the exact same driving routes. Even with the OEM thermostat I have always noticed a wide range in both engine coolant & oil temps due to changing outside ambient temps.
Last edited by LBRc7; Feb 26, 2021 at 12:21 PM.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Just a little more info for you to gauge... My '16 z51 with OEM thermostat & untuned, was seeing a consistent 160-165* (engine coolant temp) last week when outside temps were well below 50*. Now that temps are back to 68-74* my car is regularly seeing 190-199* with the exact same driving routes. Even with the OEM thermostat I have always noticed a wide range in both engine coolant & oil temps due to changing outside ambient temps.
The cars are fully validated to reach operating temp in cold weather.
Safety Car
Joined: Nov 2011
Posts: 3,714
Likes: 343
From: Norman OK
on my Camaro I also used one of the custom made t-stat housing designed to use the LS style t-stat instead of the LT t-stat that are prone to failure. It worked so well that I bought the same setup for my 19 C7Z and will be installing it in a couple of months.
Racer
Joined: Jun 2019
Posts: 386
Likes: 149
so what is the culprit here? The housing? The t-stat itself? Again, it cannot be the "opening temp" i can't imagine
Safety Car
Joined: Nov 2011
Posts: 3,714
Likes: 343
From: Norman OK
Not sure, I just know when I was putting the supercharger on my 17 Camaro SS that LT1/LT4 t-stat failures were prone to that stat. I never had any issues with the custom LS style housing or the LS t-stat so I am going that route on my Z06.
