Cooling fans running when they shouldn’t

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FatBuoy

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Hey all- found another thread on this, but the OP had the issue in the heat, so here goes. All of a sudden, the cooling fans have been coming on high for no apparent reason. I’m talking 70 out, just cruising around town, as I always have. They are LOUD! It doesn’t seem to matter if the a/c is on or not. Any initial thoughts as to what this could be? It’s new behavior at, around 60k miles, which is why I’m concerned. By the way, they don’t come on right at startup. It does it when it gets up to operating temp. And the temp is normal.


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jabroni619

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Are you sure temps are normal? Gauges often don’t tell you the full story until it’s too late.
 

blwn

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Check the coolant level in the overflow tank. If it's a little low it will make the fans run. If it is low, it might have a leak at the fitting, I hear it's pretty common
 
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FatBuoy

FatBuoy

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Check the coolant level in the overflow tank. If it's a little low it will make the fans run. If it is low, it might have a leak at the fitting, I hear it's pretty common
Thank you. It is a little low, as in I can see it in there, but it’s a couple of inches below the minimum line. Will add. Hopefully, that’s it! Nothing blocking the radiator or condenser.


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blwn

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Thank you. It is a little low, as in I can see it in there, but it’s a couple of inches below the minimum line. Will add. Hopefully, that’s it! Nothing blocking the radiator or condenser.

Sounds like you're on the right track. Now try and see if you can find where it's losing coolant. When it's low in the overflow, the fans typically come on as soon as you start it, not just when it's up to temp. Adding coolant should help, but I'm guessing you have a slow leak at the overflow tank fitting, or you're having water pump problems. I think there was someone on here recently that was overheating similar to you and required the pump to be replaced.
 

goblues38

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do you have the 4 scan mod that shows actual coolant temp? Mine bounces between 190 and 215 during normal driving. When I am in full ass hat mode with the gas pedal, it will jump to 230 and the fans will kick on. Never have I seen it above 240. And the fans turn off again when it drops below 220.
 

Bluto

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Fans will also come on for high transmission temperatures. One more thing to double check.
 
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FatBuoy

FatBuoy

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do you have the 4 scan mod that shows actual coolant temp? Mine bounces between 190 and 215 during normal driving. When I am in full ass hat mode with the gas pedal, it will jump to 230 and the fans will kick on. Never have I seen it above 240. And the fans turn off again when it drops below 220.
I don’t.


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FatBuoy

FatBuoy

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Sounds like you're on the right track. Now try and see if you can find where it's losing coolant. When it's low in the overflow, the fans typically come on as soon as you start it, not just when it's up to temp. Adding coolant should help, but I'm guessing you have a slow leak at the overflow tank fitting, or you're having water pump problems. I think there was someone on here recently that was overheating similar to you and required the pump to be replaced.
So, is it possible to loose that coolant over 60k miles and 3.5 years without ever adding any? Upon initial inspection, I did’t see any sign of leakage.


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