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Discussion Starter · #1 ·
Hello,

I noticed on my 2012 Cruze 1.4L that the radiator fan goes high (audible inside the car) when the AC is running in sitting traffic. It is pretty warm at the moment - over 90F ambient temperature as reported by car. The radiator fan cycles 2 seconds on then 15 seconds off. As soon as the car starts moving over 20mph, this goes away and the fan is no longer audible.

I monitor the coolant temperature readout and it stays between 210F-217F and all the fluids are at a good level. I've owned the car since new and do not remember this happening before.

Is this normal? This does not happen when 1) moving at highway speeds with AC on or 2) idling in traffic with AC off.

Thank you.
 

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This is normal when it is so hot outside. The air movement from the radiator fan is also used to move the heat away from the A/C Condenser which is in front of the radiator. When the vehicle is moving fast enough the air is naturally pushed through the radiator so the fan is no longer required.
 
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Most cars are doing that now. If not all by now.

Fan runs in the same manner as coolant.
When ac is on. High pressure sensor kicks it on.

It's no longer constant on


However. It shouldn't be jet speed. It should be low speed. You can barely hear it if there's no other noise to drown it out.

First time I seen fan off and on was a 15 Toyota truck. Then I bought my 17 cruze and it does the same thing.
 

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Discussion Starter · #5 ·
This is normal when it is so hot outside. The air movement from the radiator fan is also used to move the heat away from the A/C Condenser which is in front of the radiator. When the vehicle is moving fast enough the air is naturally pushed through the radiator so the fan is no longer required.
Most cars are doing that now. If not all by now.

Fan runs in the same manner as coolant.
When ac is on. High pressure sensor kicks it on.

It's no longer constant on


However. It shouldn't be jet speed. It should be low speed. You can barely hear it if there's no other noise to drown it out.

First time I seen fan off and on was a 15 Toyota truck. Then I bought my 17 cruze and it does the same thing.

That makes sense. I can hear the fan if the radio is off - it sounds like the engine revving. Would that be considered normal or too loud?
 

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Thank you. Can you hear the fan in the cabin? The fan on my cruze sounds like engine rev when it cycles.
Yes when I'm sitting in the car at idle and radio off. I usually wait for it to cycle off to lower the coolant temperature. I have a scan gage on the center console. The fan does have low and high speeds. I can hear it when it's running on high speed. Low speed is very quiet even if I'm standing outside.

On my 2018 Cruze I don't know what the fan is doing because it's a Diesel.
 

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You have to have airflow across the condenser when the A/C is running,
otherwise it cant dispose of its heat.
No airflow, means A/C that doesnt cool...
 

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Discussion Starter · #9 ·
I verified that fan is not running with AC ON (car in park). It cycles to medium for 2sec and then turns off. Repeat.

Does that mean the low speed is burnt out? Or is it possible that fan does not always run with AC ON?
 

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What you consider medium is probably low speed.

Yes your fan is normal. As explained above.
It runs off the high pressure sensor switch.

Gone are the days of compressor power and constant on.
 

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It may use a thermal or pressure switch or sensor that sends info to the pcm, and it may delay the fan for a short time after the compressor engages.
If the fan only cycles on for only 2 seconds, that sounds odd.
Are you sure the compressor is staying on too?
Is the A/C cooling the interior well?
 

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Discussion Starter · #12 ·
What you consider medium is probably low speed.
That could be true.
I also realized that under normal conditions the radiator fan doesn't run at all. The only other time I have heard the fan is after stopping for gas where the coolant stays still and gets hot (> 225F) with the engine / water pump turned off for those few minutes.

I was concerned because some older posts here mention that the fan should run continuously with AC ON.
 

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Discussion Starter · #13 ·
It may use a thermal or pressure switch or sensor that sends info to the pcm, and it may delay the fan for a short time after the compressor engages.
If the fan only cycles on for only 2 seconds, that sounds odd.
Are you sure the compressor is staying on too?
Is the A/C cooling the interior well?
The AC is working pretty well and I am certain it is on for 2-3 seconds max, rest for 10 seconds and repeat. I don't know if compressor is shutting off or not. The air stays cold the whole time.
 

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That could be true.
I also realized that under normal conditions the radiator fan doesn't run at all. The only other time I have heard the fan is after stopping for gas where the coolant stays still and gets hot (> 225F) with the engine / water pump turned off for those few minutes.

I was concerned because some older posts here mention that the fan should run continuously with AC ON.
Those older posts should already know that the fan doesn't run continuously on the cruze.
 

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Should the fan cycle? Yes. Should you be able to hear it? Probably not. I think it's pretty rare for a Cruze with a good fan to jump to high (jet mode) speed. What is common is for the resistor pack to burn out so the car loses the lower speeds and it's stuck cycling at high speed.
 

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Should the fan cycle? Yes. Should you be able to hear it? Probably not. I think it's pretty rare for a Cruze with a good fan to jump to high (jet mode) speed. What is common is for the resistor pack to burn out so the car loses the lower speeds and it's stuck cycling at high speed.
2012 eco. My cooling fan is not acting as it should. What I have found so far:

Fan does cycle at medium or high speed with AC or Defrost turned on.
Fan does not turn on at any other time that I know of, or that I can hear while driving.

With engine at idle/operating temp and parked, AC and defrost not turned on:
Fan does not turn on at all. DIC temp will rise as high as 243 and decrease to as low as 190.
Coolant system is not leaking, recent new pump, thermostat and res cap.

With engine at idle/operating temp and parked; 9-low, 10-medium and 13-high relays removed:
relay 9 socket jumpered- fan runs at medium speed
relay10 socket jumpered- fan runs at medium speed
relay 13 socket jumpered- fan runs at high speed

I assume my low speed resistor has failed (it's ability to reduce current to the fan motor?) There are only 2 wires from the resistor pack to the fan motor. So when the low resistor fails, power is still passed on to the motor but only reduced by the medium resistor even though the ecm is asking for the low speed through the low speed relay?

My issue in addition to the resistor fail, is that my fan seemingly does not ever operate except for AC or defrost.
I will replace the fan assembly but what should my next test be or where should I look to have even the new fan operate correctly.

I am working on this from a limited DIY viewpoint, if my assumptions are off, I will appreciate any valid corrections.
I try to post on existing threads but will start a new one if these are too old.
Thanks to this forum
 

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There are a total of 5 cooling fan relays.
The 3 primary ( Low/Med/High), and then 2 more relays to regulate the primaries.
Its messed up, but some engineer came up with this overly complex solution to a simple problem of controlling 3 fan speeds using only 2 PCM driver taps.
They could've eliminated the other 2 control relays by just adding a third tap to the PCM, and I'll bet there is an open one available....
If you are jumpering the correct relay to trigger low speed, and it comes on, then the low speed resistor is good.
It will not default to medium speed if the low resistor is bad.
Now if low doesnt work, things will eventually heat up to the point where the PCM will trigger medium speed.
 

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There are a total of 5 cooling fan relays.
The 3 primary ( Low/Med/High), and then 2 more relays to regulate the primaries.
Its messed up, but some engineer came up with this overly complex solution to a simple problem of controlling 3 fan speeds using only 2 PCM driver taps.
They could've eliminated the other 2 control relays by just adding a third tap to the PCM, and I'll bet there is an open one available....
If you are jumpering the correct relay to trigger low speed, and it comes on, then the low speed resistor is good.
It will not default to medium speed if the low resistor is bad.
Now if low doesnt work, things will eventually heat up to the point where the PCM will trigger medium speed.
Ok thanks for that clarification. As I have read in multiple past threads, the temperature at which the 3 fan speeds are activated seems to not be published anywhere, thankfully from CTalk member personal experiences 225-230 seems to be the low speed temp. I do not see it on Alldata either.
So working backward from the fan, I should verify that all 5 relays work and that they all have power. I can check for a tutorial on that.
If possible I can try to get the coolant temp high enough while parked to see if this fan kicks on at all (without AC or defrost), but so far at idle, it did not turn on with temp up to 234.
TBC=to be continued
 

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Reading through the Alldata repair manual, cooling system description. In the thermostat description it states "thermostat is fully open at 248 degrees". My analog gauge needle moves rapidly toward H at 243-245. Does everyone's 1.4t Cruze operate at this temperature normally??

Well, have I become so overly sensitive to seeing 235+ temps on my 2012 eco DIC coolant temp screen?? The fact that high coolant/engine temperature has such a catastrophic effect on the 1.4T engine life is certainly ingrained in my daily use of the car. Much deserved driving enjoyment has been pushed aside. Thoughts of impending internal engine damage cause my hand to involuntarily move to the cabin temp and fan controls to manually bleed off coolant heat so that my read-out stays below 240... haHA!! no boiling orange liquid is going to stop me today!

Meanwhile 87 other 2013-16.5 gen 1 cruzen within 500 yards of mine are enjoying their commute completely unaware of how close they are to head gasket obliteration... needle 1 click below center, uh ok, beautiful day today. Perhaps an update to eliminate my DIC coolant temp screen would be good for my state of mind...

Did Chevy Vega owners go through this...

onward
 

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2012 eco. My cooling fan is not acting as it should. What I have found so far:

Fan does cycle at medium or high speed with AC or Defrost turned on.
Fan does not turn on at any other time that I know of, or that I can hear while driving.

With engine at idle/operating temp and parked, AC and defrost not turned on:
Fan does not turn on at all. DIC temp will rise as high as 243 and decrease to as low as 190.
Coolant system is not leaking, recent new pump, thermostat and res cap.

With engine at idle/operating temp and parked; 9-low, 10-medium and 13-high relays removed:
relay 9 socket jumpered- fan runs at medium speed
relay10 socket jumpered- fan runs at medium speed
relay 13 socket jumpered- fan runs at high speed

I assume my low speed resistor has failed (it's ability to reduce current to the fan motor?) There are only 2 wires from the resistor pack to the fan motor. So when the low resistor fails, power is still passed on to the motor but only reduced by the medium resistor even though the ecm is asking for the low speed through the low speed relay?

My issue in addition to the resistor fail, is that my fan seemingly does not ever operate except for AC or defrost.
I will replace the fan assembly but what should my next test be or where should I look to have even the new fan operate correctly.

I am working on this from a limited DIY viewpoint, if my assumptions are off, I will appreciate any valid corrections.
I try to post on existing threads but will start a new one if these are too old.
Thanks to this forum

YOU EVER FIND A FIX??!?
 
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