Radiator Fan On - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

eric sakai · 06-24-2024, 10:03 PM

I changed antifreeze.
When on freeway at speed I cannot hear fan because of outside noise, but running about 230F. It seems soon as 230F fan comes on and stays on.
Soon as off freeway, cool morning at speed, I can hear fan at full blast. It was not like this before. I would think freeway speed should keeps engine cool enough for fan to be off.
What is causing the fan to be on?
Thanks in advance.

Bee · 06-24-2024, 10:19 PM

It sounds like there might be either a little bit of air trapped in the coolant or maybe the level is a tad low. Not enough to cause it to go into limp mode but just a bit to make it run hot.

*SSE 4 2SS* · 06-25-2024, 01:56 AM

Yup, air in the system is the most likely cause....

Rusty Shackleford · 06-25-2024, 10:52 AM

Does the fan remain running at full speed after you shut the car off? Does the temp gauge show any reading at all?

It's a common issue for these year range gm vehicles to default the fan into a wide open state when the thermostat fails (sticks open) or the coolant temp sensor fails. As I understand it, if the engine doesn't get up to operating temp within a given amount of time then the fan defaults to full speed. Either, or both, are fairly easy and cheap to replace, then you just need to clear the code afterward and things would return to normal.

THe way you describe your issue, it may or may not be what I describe above.

bsn · 06-25-2024, 06:07 PM

Any chance you have the AC on?

06-24-2024, 10:03 PM	#1
eric sakai Drives: 2015 Join Date: Jan 2016 Location: Hawaii Posts: 41	Radiator Fan On I changed antifreeze. When on freeway at speed I cannot hear fan because of outside noise, but running about 230F. It seems soon as 230F fan comes on and stays on. Soon as off freeway, cool morning at speed, I can hear fan at full blast. It was not like this before. I would think freeway speed should keeps engine cool enough for fan to be off. What is causing the fan to be on? Thanks in advance.

06-24-2024, 10:19 PM	#2
Bee Drives: SS/RS - Rally Yellow Join Date: May 2009 Location: Levittown, PA Posts: 642 View My Garage	It sounds like there might be either a little bit of air trapped in the coolant or maybe the level is a tad low. Not enough to cause it to go into limp mode but just a bit to make it run hot. __________________ Check out my build here. SEPA5 South Eastern Pennsylvania 5th Gen Camaro Club

06-25-2024, 01:56 AM	#3
SSE 4 2SS Boosted Moderator Drives: Bone Stock LS3 Join Date: Sep 2009 Location: Marion Tx Posts: 15,799	Yup, air in the system is the most likely cause.... __________________ If the car feels like it is on rails, you are probably driving too slow. -Ross Bentley Horsepower is how fast you hit the wall. Torque is how far you take the wall with you. “If everything seems under control, you're just not going fast enough.” Mario Andretti If you can turn, you ain't going fast enough...

06-25-2024, 10:52 AM	#4
Rusty Shackleford Drives: 2012 Camaro 2SS Join Date: Jun 2023 Location: Texas Posts: 86	Does the fan remain running at full speed after you shut the car off? Does the temp gauge show any reading at all? It's a common issue for these year range gm vehicles to default the fan into a wide open state when the thermostat fails (sticks open) or the coolant temp sensor fails. As I understand it, if the engine doesn't get up to operating temp within a given amount of time then the fan defaults to full speed. Either, or both, are fairly easy and cheap to replace, then you just need to clear the code afterward and things would return to normal. THe way you describe your issue, it may or may not be what I describe above.

06-25-2024, 06:07 PM	#5
bsn Drives: 2013 ZL1 Join Date: Sep 2021 Location: Virginia Posts: 469	Any chance you have the AC on?