2001 C5 operating temperature
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Instructor
Joined: Jun 2015
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From: Ohatchee Alabama
2001 C5 operating temperature
Good morning Forum. My C5 normal operating temp was basically between 196 and 201. I think this is within the so called "Sweet Spot". My water pump started leaking a few weeks ago and my temperature started fluctuating more than what I would call normal. So I had it changed. At the same time, I had them change the thermostat (came with the water pump). Now it seem the normal operating temperature is between 172-178.
1) Is this ok, or should I have them replace the thermostat again?
2) Is there now a possible issue with the temperature sensor?
3) Possibility of just the wrong thermostat?
4) what will it hurt to leave it run at the cooler temperature?
1) Is this ok, or should I have them replace the thermostat again?
2) Is there now a possible issue with the temperature sensor?
3) Possibility of just the wrong thermostat?
4) what will it hurt to leave it run at the cooler temperature?
Last edited by Clayton59; Mar 1, 2020 at 07:53 AM. Reason: Question added
1/4 mile/AutoX
Joined: Jun 2014
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From: Buffalo Texas
what stat did they install ??? 160 I presume !!! I am a the very few here rather to have my engine run cool (heat kills everything on a car) I run a 180 stat and mine runs in the 190 range, I think that's perfect !!!
Burning Brakes
Joined: Jan 2006
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From: Olathe Kansas
Yup, It sounds like they installed a lower temp TStat..
If your car is only running in the 170's... That's too low.. Not good for engine longevity.
The LS motors like to run a little warm.. its better for ring seal, wear, etc
The 190's to me is the sweet spot.
I run a 180 TStat, so it usually runs about 190. My fans are tuned to turn on at 202 low speed and 212 high speed
If your car is only running in the 170's... That's too low.. Not good for engine longevity.
The LS motors like to run a little warm.. its better for ring seal, wear, etc
The 190's to me is the sweet spot.
I run a 180 TStat, so it usually runs about 190. My fans are tuned to turn on at 202 low speed and 212 high speed
Pro
Joined: Jan 2015
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OP sounds like it’s running fine and you’re not running the car long enough to see temps above 178+
A thermostat does not run the engine at lower temps. The thermostat opens at the temp listed to allow coolant to flow into the block. either at 160, 170, or 180. Unless you live in Siberia, I would first start by running the engine longer to get above 178 if that’s your concern. But most likely the lower temps you are seeing are due to a properly working water pump and new coolant. Lower degree thermostat does not have any ill effects.
A thermostat does not run the engine at lower temps. The thermostat opens at the temp listed to allow coolant to flow into the block. either at 160, 170, or 180. Unless you live in Siberia, I would first start by running the engine longer to get above 178 if that’s your concern. But most likely the lower temps you are seeing are due to a properly working water pump and new coolant. Lower degree thermostat does not have any ill effects.
Last edited by C6Z_LS7; Mar 1, 2020 at 11:31 PM.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,439
Likes: 2,184
From: Buffalo Texas
OP sounds like it’s running fine and you’re not running the car long enough to see temps above 178+
A thermostat does not run the engine at lower temps. yes it does !!! The thermostat opens at the temp listed to allow coolant to flow into the block. wrong the coolant circulates in the block until the stat slowly opens allowing coolant to start flowing to the radiator either at 160, 170, or 180. Unless you live in Siberia, I would first start by running the engine longer to get above 178 if that’s your concern. But most likely the lower temps you are seeing are due to a properly working water pump and new coolant. Lower degree thermostat does not have any ill effects.
A thermostat does not run the engine at lower temps. yes it does !!! The thermostat opens at the temp listed to allow coolant to flow into the block. wrong the coolant circulates in the block until the stat slowly opens allowing coolant to start flowing to the radiator either at 160, 170, or 180. Unless you live in Siberia, I would first start by running the engine longer to get above 178 if that’s your concern. But most likely the lower temps you are seeing are due to a properly working water pump and new coolant. Lower degree thermostat does not have any ill effects.
Pro
Joined: Jan 2015
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wow relax... why are you yelling? Operating temperatures are not controlled by the thermostat, its all on the cooling capacity and flow through the radiator and block. Yes, you're right...coolant does circulates through the block. I should have been more clear, once the stat opens it allows the coolant flow through the entire cooling system. The lower thermostat just opens up earlier but the operating temperature will have the same result unless other changes are made. Sounds like the cooling system is doing its job. On a stock tune, engine, radiator... to help answer the OPs question/concern, no ill effects. Unless you live in severe cold weather, it might take longer to warm up the car.
Clayton59, do you know what thermostat came with the water pump?
Clayton59, do you know what thermostat came with the water pump?
Last edited by C6Z_LS7; Mar 2, 2020 at 11:57 PM.
Banned Scam/Spammer
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From: Machineguns, because I don’t compromise
With my 160 stat oil temp can be 205 and up to 240 running wide open in the hills. I’m glad the stat isn’t staying closed until factory 195.
Instructor
Joined: Aug 2018
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I would say, as long as you get your oil above 180*F before beating on it, above 212*F for at least 30 mins once a week ( to burn off condensation) and don't get the oil above 240*F (maybe 250 at most? I think the oil start breaking down around 275?), you are in good shape...
Coolant temp is less important than oil temp, as long as you don't overheat and stay near the normal range.... I believe, like other have said, the power sweet spot is around 180*F.
Coolant temp is less important than oil temp, as long as you don't overheat and stay near the normal range.... I believe, like other have said, the power sweet spot is around 180*F.
Last edited by VFR RC46; Mar 3, 2020 at 08:40 AM.
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1/4 mile/AutoX
Joined: Jun 2014
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From: Buffalo Texas
wow relax... why are you yelling? Operating temperatures are not controlled by the thermostat, its all on the cooling capacity and flow through the radiator and block. Yes, you're right...coolant does circulates through the block. I should have been more clear, once the stat opens it allows the coolant flow through the entire cooling system. The lower thermostat just opens up earlier but the operating temperature will have the same result unless other changes are made. Sounds like the cooling system is doing its job. On a stock tune, engine, radiator... to help answer the OPs question/concern, no ill effects. Unless you live in severe cold weather, it might take longer to warm up the car.
Clayton59, do you know what thermostat came with the water pump?
Clayton59, do you know what thermostat came with the water pump?
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,439
Likes: 2,184
From: Buffalo Texas
the engine temp will generally run about 10 degrees above set stat, the stat does not open all at once but will slowly open and close on temp, a 180 stat will get the engine to that temp then slowly open to the rad bring the rad temp eventually to 190, as the the ambient air (less than 100 degrees normally) goes though the rad it cools the coolant back down to the stat temp, because the stat dictates it !!!!!!!! I am amazed how few get this ???? yes it will run hotter than the 10 over from time to time but can eventually get back down to stat temp. for example our C6 Z06 (600 to the rear) with a 170 stat will go as high as 217 (the highest we have seen) during 16 AutoX runs, then on the way home will cool back to 185 or so !!!
Last edited by Pounder; Mar 3, 2020 at 10:46 AM.
Pro
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Just because you're yelling doesn't prove your points. And nobody cares about how many C5s and C6s you have and what's perfect you. You contradict yourself on operating temps and stats. Clearly I'm not the one who knows nothing about cooling systems. You're hijacking this thread and making it about you. Answer the OP, there is no ill effects running a slightly lower degree stat
Last edited by C6Z_LS7; Mar 3, 2020 at 04:38 PM.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,439
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From: Buffalo Texas
Just because you're yelling doesn't prove your points. And nobody cares about how many C5s and C6s you have and what's perfect you. You contradict yourself on operating temps and stats. Clearly I'm not the one who knows nothing about cooling systems. You're hijacking this thread and making it about you. Answer the OP, there is no ill effects running a slightly lower degree stat
Last edited by Pounder; Mar 3, 2020 at 06:32 PM.
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Safety Car
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From: Da U.P.
The trick to longevity is for oil to be in the 200-220 range. If you run a 160 stat and don't rip on the car, the oil will never hit 200+ and will cause more wear. What that truly means is anyone's guess. Maybe your motor lasts 300k instead of 400k?
Race Director
Joined: Apr 2007
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From: South Western Ontario
wow relax... why are you yelling? Operating temperatures are not controlled by the thermostat, its all on the cooling capacity and flow through the radiator and block. Yes, you're right...coolant does circulates through the block. I should have been more clear, once the stat opens it allows the coolant flow through the entire cooling system. The lower thermostat just opens up earlier but the operating temperature will have the same result unless other changes are made. Sounds like the cooling system is doing its job. On a stock tune, engine, radiator... to help answer the OPs question/concern, no ill effects. Unless you live in severe cold weather, it might take longer to warm up the car.
The thermostat begins opening at it's rated temperature and then opens fully from there as the coolant temperature increases another 10* to 20*. The thermostat isn't just open or closed.
Given enough radiator and fan, the engine will ALWAYS run just above the thermostat rated temperature. The thermostat will partially open and regulate the radiator flow to maintain the coolant temperature. My C5 with the stock 193* thermostat runs just a little over 193* at the highway speeds I normally drive until I slow way down or stop and there is no longer enough airflow. At that point, the coolant rises until the fans come on and once again provide enough airflow. My 65 Impala with electric fans does the same thing.
The fact the OP's car is running at a lower temperature after the thermostat was changed to a lower temperature rated thermostat also proves the thermostat regulates the lower end of the coolant temperature.
There wouldn't be thermostats with different temperature ratings sold if they didn't change the operating temperature of the engine.
Race Director
Joined: Apr 2007
Posts: 11,150
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From: South Western Ontario
The OLM counts 50*C oil the same as 100*C oil, so GM doesn't seem to believe the oil needs to get that hot to have a full life.
My C5 on the 25 minute drive to work barely gets the oil to 190*F. Sometimes it's even cooler when I park it. On much longer highway drives the oil temperature typically won't go above 200*F either. And that's with the stock thermostat.