Cooling system
Thread Starter
Racer
Joined: Feb 2005
Posts: 374
Likes: 4
From: decatur ga
Cooling system
I m working on one of my club member's 96..The fans are not coming on
until around 226.The car is also pushing water out of the tank, when hot. I'm buying a system tester tomorrow to check the cooling system. Should the fans come on sooner. My 93 comes on around 200 and stays on until around 185.
until around 226.The car is also pushing water out of the tank, when hot. I'm buying a system tester tomorrow to check the cooling system. Should the fans come on sooner. My 93 comes on around 200 and stays on until around 185.
Race Director
Joined: Oct 2005
Posts: 11,772
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
I m working on one of my club member's 96..The fans are not coming on
until around 226.The car is also pushing water out of the tank, when hot. I'm buying a system tester tomorrow to check the cooling system. Should the fans come on sooner. My 93 comes on around 200 and stays on until around 185.
until around 226.The car is also pushing water out of the tank, when hot. I'm buying a system tester tomorrow to check the cooling system. Should the fans come on sooner. My 93 comes on around 200 and stays on until around 185.
They didn't operate at those temps from the factory.
1996 factory fan settings:
The PCM will command low speed fans ON at
104°C (219°F) and OFF at 98°C (207°F) and, high
speed fans ON at 109°C (228°F) and OFF at 103°C (214°F)
Note: On the '96, both fans run together (either low or high).
Also, Running the A/C will cause the fans to run.
Do some searching around here, and you'll find enough posts on this subject to keep you busy for days.
If you have the proper coolant mix and pressure cap, your coolant won't "Boil" until over 260°F
Your cooling fans will run at a slower speed when they first come on, and then move to a higher speed as the temps reaches approx. 228°F (based on the reading from the digital gauge).
While sitting in stop and go traffic: 217°F - 235°F
Moving at any speed over approx. 40 mph: 190°F - 200°
Here are a few to get you started:
https://www.corvetteforum.com/forums...lant-temp.html
https://www.corvetteforum.com/forums...s-too-hot.html
https://www.corvetteforum.com/forums...ioning-on.html
https://www.corvetteforum.com/forums...ating-but.html
https://www.corvetteforum.com/forums...-question.html
https://www.corvetteforum.com/forums...r-heating.html
https://www.corvetteforum.com/forums...-too-high.html
Last edited by RollaMo-LT4; Aug 12, 2015 at 08:39 PM.
Thread Starter
Racer
Joined: Feb 2005
Posts: 374
Likes: 4
From: decatur ga
cooling
What would make them not come at 219.they only come on high at 228?
Someone has reprogrammed your fan settings.
They didn't operate at those temps from the factory.
1996 factory fan settings:
The PCM will command low speed fans ON at
104°C (219°F) and OFF at 98°C (207°F) and, high
speed fans ON at 109°C (228°F) and OFF at 103°C (214°F)
Note: On the '96, both fans run together (either low or high).
Also, Running the A/C will cause the fans to run.
Do some searching around here, and you'll find enough posts on this subject to keep you busy for days.
If you have the proper coolant mix and pressure cap, your coolant won't "Boil" until over 260°F
Your cooling fans will run at a slower speed when they first come on, and then move to a higher speed as the temps reaches approx. 228°F (based on the reading from the digital gauge).
While sitting in stop and go traffic: 217°F - 235°F
Moving at any speed over approx. 40 mph: 190°F - 200°
Here are a few to get you started:
https://www.corvetteforum.com/forums...lant-temp.html
https://www.corvetteforum.com/forums...s-too-hot.html
https://www.corvetteforum.com/forums...ioning-on.html
https://www.corvetteforum.com/forums...ating-but.html
https://www.corvetteforum.com/forums...-question.html
https://www.corvetteforum.com/forums...r-heating.html
https://www.corvetteforum.com/forums...-too-high.html
They didn't operate at those temps from the factory.
1996 factory fan settings:
The PCM will command low speed fans ON at
104°C (219°F) and OFF at 98°C (207°F) and, high
speed fans ON at 109°C (228°F) and OFF at 103°C (214°F)
Note: On the '96, both fans run together (either low or high).
Also, Running the A/C will cause the fans to run.
Do some searching around here, and you'll find enough posts on this subject to keep you busy for days.
If you have the proper coolant mix and pressure cap, your coolant won't "Boil" until over 260°F
Your cooling fans will run at a slower speed when they first come on, and then move to a higher speed as the temps reaches approx. 228°F (based on the reading from the digital gauge).
While sitting in stop and go traffic: 217°F - 235°F
Moving at any speed over approx. 40 mph: 190°F - 200°
Here are a few to get you started:
https://www.corvetteforum.com/forums...lant-temp.html
https://www.corvetteforum.com/forums...s-too-hot.html
https://www.corvetteforum.com/forums...ioning-on.html
https://www.corvetteforum.com/forums...ating-but.html
https://www.corvetteforum.com/forums...-question.html
https://www.corvetteforum.com/forums...r-heating.html
https://www.corvetteforum.com/forums...-too-high.html
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
No. The '96 operates differently. RollaMo-LT4 covered it pretty thoroughly.
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
I would suspect that the dash reading and engine readings are not the same and the ECM is turning the fan on at 219 according to the ECM temp sensor, but the dash sensor might be reading 228 degrees.
Melting Slicks
Joined: May 2013
Posts: 2,692
Likes: 349
From: Sacramento California
Everyone else is addressing the temperature issue pretty well. But about this... it is normal for the system to push coolant from the surge tank (black tank with radiator cap) into the recovery reservoir (white container ahead of passenger front tire). That's why there are two levels on the stick, cool and hot. This pushing and pulling of coolant during heat cycles is very normal in modern engines, and helps to remove air from the system after service.
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Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Everyone else is addressing the temperature issue pretty well. But about this... it is normal for the system to push coolant from the surge tank (black tank with radiator cap) into the recovery reservoir (white container ahead of passenger front tire). That's why there are two levels on the stick, cool and hot. This pushing and pulling of coolant during heat cycles is very normal in modern engines, and helps to remove air from the system after service.
Aside from when the fans come on, the temps seem to be in the normal window. First item I would check or replace is the radiator cap and make sure it is the correct pressure for the car. I believe 15 pounds is the correct pressure cap.
Race Director
Joined: Oct 2005
Posts: 11,772
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
No, it's not normal for it to push coolant into the tank where it will fill up and over flow. It will push some coolant into the tank like any other car but usually not above the hot line indicator.
Aside from when the fans come on, the temps seem to be in the normal window. First item I would check or replace is the radiator cap and make sure it is the correct pressure for the car.
Aside from when the fans come on, the temps seem to be in the normal window. First item I would check or replace is the radiator cap and make sure it is the correct pressure for the car.
As I mentioned in my reply above:
If you have the proper coolant mix and pressure cap, your coolant won't "Boil" until over 260°F
Plain water will boil at 212°F at sea level.
Thread Starter
Racer
Joined: Feb 2005
Posts: 374
Likes: 4
From: decatur ga
cooling
hot vette
It is not boiling ,just pushing out.
I blew out to tank lines with air.I discounnected at the tank.I pushed water out of the tank on me. I also connected my scanner to the car the reading were only one degree off. It showed it was coming on at 227
I need to know this should the fans come low speed 212 or 227?
Thanks everyone
96 corvette
.
As I mentioned in my reply above:
Of course if the pressure cap isn't operating correctly, the coolant will boil over at a much lower temp.
Plain water will boil at 212°F at sea level.
It is not boiling ,just pushing out.
I blew out to tank lines with air.I discounnected at the tank.I pushed water out of the tank on me. I also connected my scanner to the car the reading were only one degree off. It showed it was coming on at 227
I need to know this should the fans come low speed 212 or 227?
Thanks everyone
96 corvette
.
As I mentioned in my reply above:
Of course if the pressure cap isn't operating correctly, the coolant will boil over at a much lower temp.
Plain water will boil at 212°F at sea level.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I recently found out that there is a city in Missouri called Rolla, so Rolla, MO. I thought his name was something like "rolling more" or similar to that...
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
OK. My understanding is that both fans turn on in slow mode at 228° and go to fast mode at 238°. Is that not the case?
I recently found out that there is a city in Missouri called Rolla, so Rolla, MO. I thought his name was something like "rolling more" or similar to that...
I recently found out that there is a city in Missouri called Rolla, so Rolla, MO. I thought his name was something like "rolling more" or similar to that...
I thought the same thing about "Rolla mo"
Melting Slicks
Joined: May 2013
Posts: 2,692
Likes: 349
From: Sacramento California
Sometimes I feel like I am not speaking English
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
I took his initial comment as the overflow tank because he said "The car is also pushing water out of the tank, when hot".
Why mention coolant pushes out of the surge tank when its hot because that a given and what should happen (just not excessively).
I may viewed it in my own way.......or is it me.
Sometimes I feel like I am not speaking English
Race Director
Joined: Oct 2005
Posts: 11,772
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
Yes, I live in Rolla, MO and have a '96 LT4 Corvette
So, RollaMo-LT4
And the temps I posted above for the '96 came right out of the '96 FSM
