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2010 Cts 4 runs hot sometimes and run good sometimes not sure what it is I removed thermostat and drove it to see if it was that but it did the same thing a few days later anyone know what it could be ? Also have code po480 and po117
 

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2010 Cts 4 runs hot sometimes and run good sometimes not sure what it is I removed thermostat and drove it to see if it was that but it did the same thing a few days later anyone know what it could be ? Also have code po480 and po117
Welcome.

First, make sure your coolant is at the proper level.
P0480 is a cooling fan malfunction. Check the fan for wiring issues and/or proper operation. This code likely caused the second code to pop...

 

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Welcome.

First, make sure your coolant is at the proper level.
P0480 is a cooling fan malfunction. Check the fan for wiring issues and/or proper operation. This code likely caused the second code to pop...

Welcome.

First, make sure your coolant is at the proper level.
P0480 is a cooling fan malfunction. Check the fan for wiring issues and/or proper operation. This code likely caused the second code to pop...

does the fan supposed to stay on when running the a/c ?
 

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The oil is clean no smoke out the tail pipe and I used the block tester to check engine it pass color never changed Im thinking it鈥檚 the coolant reservoir cap it has no pressure on it not sure cause most the coolant boiled out reservoir but I was able to take cap right out with no pressure and I tested the block while it was steaming out reservoir with tester any advice
 

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The oil is clean no smoke out the tail pipe and I used the block tester to check engine it pass color never changed Im thinking it鈥檚 the coolant reservoir cap it has no pressure on it not sure cause most the coolant boiled out reservoir but I was able to take cap right out with no pressure and I tested the block while it was steaming out reservoir with tester any advice
Is your coolant fan working when it should, or at all?
 

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I turn the a/c on the fan turns on and a few minutes it鈥檚 Off when I seen the temp Start to go up I turn a/c off and fan is on when I turn the engine off
 

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I turn the a/c on the fan turns on and a few minutes it鈥檚 Off when I seen the temp Start to go up I turn a/c off and fan is on when I turn the engine off
You need to check your fuse box along with a wiring diagram to identify all relays and any fuses associated with the engine cooling control. The fan is probably turning off because, its speed is controlled by the PCM (engine computer), based on two inputs; a/c system pressure which varies with weather conditions and therefore varies the speed of the fan, which may not be sufficient enough to cool the motor and by engine coolant temp.

I suspect the circuits are separate and only the a/c circuit is working and is not sufficient enough to generate the speed necessary to cool the engine under your current conditions, as a result, the temp that shuts the a/c off is being reached, which also shuts the fan off leaving you with no fan operation as coolant temps continue to rise.

Fan control.png
 

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You need to check your fuse box along with a wiring diagram to identify all relays and any fuses associated with the engine cooling control. The fan is probably turning off because, its speed is controlled by the PCM (engine computer), based on two inputs; a/c system pressure which varies with weather conditions and therefore varies the speed of the fan, which may not be sufficient enough to cool the motor and by engine coolant temp.

I suspect the circuits are separate and only the a/c circuit is working and is not sufficient enough to generate the speed necessary to cool the engine under your current conditions, as a result, the temp that shuts the a/c off is being reached, which also shuts the fan off leaving you with no fan operation as coolant temps continue to rise.

View attachment 582803
So the fan is supposed to stay on ? And not turn off and on with a/c? And how does it supposed to operate without the a/c on ?
 

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So the fan is supposed to stay on ? And not turn off and on with a/c? And how does it supposed to operate without the a/c on ?
It is computer controlled and does not turn on and off like the earlier fans. It is pulsed to maintain a speed range.The a/c is turned off when the coolant temp exceeds a certain point. I don't know it for sure, but suspect the circuits are separate, so if the a/c circuit is shut down and the coolant temp sensor circuit is inop, you have no fan operation when the a/c is shut down due to the overheat.

Since the a/c circuit relies on system pressure to command fan speed, if it is not reaching high system pressures, the fan is not being commanded on at the higher speeds and is therefore under cooling relative to the need.
 

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Definitely check into the wiring arrangement. 2008 is the only year for the second generation that uses a dual fan arrangement as in my case. You have a single fan that should also have a resistor. This brings into question weather, or not there is a dual circuit control, or single. If you have consistent fan operation with a/c on and no fan operation with a/c off, that suggests to me that the engine coolant temp circuit is not turning the fan on.

If the fan does come on without the a/c and the motor still ends up running hot, that's a pretty good indication that the high speed segment of the resistor is burned out and the engine is overheating because the cooling fan is under speed. You should also reinstall the thermostat, because its absence may be interfering with the flow metering in an adverse way. The thermostat housing is like a mini maze, so maybe it's possible you have an air pocket in the mix also.

This is what the part looks like;

ACDELCO 25881844

 
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