# My 2011 Cruze LT revs when the Ac is on (new to forum)



## Themaverickdude (Jun 20, 2016)

For the past year my Cruze has been making a reving sound when my Ac is turned on. It doesn't actually rev the engine, I think it is the fan kicking to high gear for no reason at the front of my car. 

I don't know the first thing about cars but there is no check engine light or indicators that something is wrong and when I take it to the dealership no one can pin the problem. 

I have googled the issue but I can't find anything specific to my problem so I turned to this forum. I hope someone can identify the problem and help me fix it.

Hope I posted this in the right area.

Thanks


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## obermd (Mar 3, 2012)

The A/C does require additional air flow to work so it may very well be the fan speeding up to provide the air flow.


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## Themaverickdude (Jun 20, 2016)

It will speed all the way up then stop then a few seconds later do it again. Over and over.

I can't tell if it does it when I'm driving but it is excessive when I'm in idle.

I bought my car brand new in 2011 and it did not always do this.


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## Philb (Jun 18, 2016)

I would try opening the hood and checking to see if the fan is off with the A/C off then turn the A/C on and see if the fan starts. It may make a difference if the car is cold vs. at operating temperature as well.


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## Themaverickdude (Jun 20, 2016)

It does it less when the ac is off but it will still do it. The gaps between the rev of the fan are greater.

When I go through a drive thru and I'm there for awhile I will cut my Ac off and it seems to help but it doesn't stop it completely.


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## jmlo96 (May 2, 2015)

Just speculation here, but if you have a 2011 1.4 t and ran your oil changes out long your oil passages may be started to get clogged up. When they clog up, the turbo has a hard time getting cool oil and the computer will turn the fan up to help cool things down. Having the AC on will only make things hotter, and like obermd said the computer will also turn the fan on for extra airflow. Again I'm only speculating.


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## jblackburn (Apr 14, 2012)

Themaverickdude said:


> It will speed all the way up then stop then a few seconds later do it again. Over and over.
> 
> I can't tell if it does it when I'm driving but it is excessive when I'm in idle.
> 
> I bought my car brand new in 2011 and it did not always do this.


I'd start with a possible bad fan or bad fan relay - there have been a few issues with these on these cars. The fan's lower speed isn't operating, or pressures are getting too high that it kicks into high speed to bring down high side pressures at the condensor.

Pop the hood with AC on and see if the fan is running at low speed AT ALL.

Also make sure that you've still got coolant in the overflow tank near the windshield. Low coolant could cause the fan to go crazy too.


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## Themaverickdude (Jun 20, 2016)

This is great how much help I'm getting thanks so much

Here are some videos I just went out to my car to take. Might help some with what I'm trying to describe.

https://youtu.be/NXpwrFl22EM

^the fan right after I turned my car on^

https://youtu.be/95sWBzz8100

^if anyone is curious on how it sounds inside


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## Themaverickdude (Jun 20, 2016)

The Ac was on the lowest setting in the videos I uploaded btw


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## jmlo96 (May 2, 2015)

Oh yeah that fan is definitely on full speed. Did you check your coolant like Jblackburn said? Also, what is your engine temperature gauge reading? It should generally hover a little before halfway. I'd be skeptical of the relay because the one's I have seen with the relay failure the fans get stuck on, or don't turn on at all.


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## jblackburn (Apr 14, 2012)

Yes, looks like full speed and then straight to off.

The fan motor has multiple windings, and the relay has 3 speeds that it can put it on (low, med, high). High grounds straight to 12V as a fail-safe. 

I believe one of the two is to blame. I have had the relay in another car not work on low, yet worked on high speed, but the fans themselves seem to be the common failure point in Cruzes.


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## Themaverickdude (Jun 20, 2016)

I haven't checked the coolant I just ran out to my car while here at the office but I will. The temperature gauge reads normal exactly how you said it should and it never jumps one way or another.


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## Themaverickdude (Jun 20, 2016)

jblackburn said:


> Yes, looks like full speed and then straight to off.
> 
> The fan motor has multiple windings, and the relay has 3 speeds that it can put it on (low, med, high). High grounds straight to 12V as a fail-safe.
> 
> I believe one of the two is to blame. I have had the relay in another car not work on low, yet worked on high speed, but the fans themselves seem to be the common failure point in Cruzes.


How should I go about fixing this? Could a common mechanic check and fix that problem or do I need to take it to the dealership?


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## Robby (Mar 1, 2013)

Themaverickdude said:


> How should I go about fixing this? Could a common mechanic check and fix that problem or do I need to take it to the dealership?


You are sort of between a rock and a hard spot......you likely need the dealer for a solid diagnosis and, if it is the fan module, you have to buy the fan assembly.
But, you wouldn't want to just replace the assembly without a solid diagnosis.

If it is the fan assembly I think they are much less expensive from places like Rock Auto.......but you still need to install it.
Not difficult for mechanically inclined sorts with tools but may be daunting for a novice.

Rob


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## Themaverickdude (Jun 20, 2016)

Thank you


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## jblackburn (Apr 14, 2012)

Themaverickdude said:


> How should I go about fixing this? Could a common mechanic check and fix that problem or do I need to take it to the dealership?


Id think a voltmeter at the connections to the fan itself would be a good start. A common mechanic or even a mechanically inclined buddy could start there.


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## ChevyGuy (Dec 13, 2014)

jblackburn said:


> The fan motor has multiple windings, and the relay has 3 speeds that it can put it on (low, med, high). High grounds straight to 12V as a fail-safe.


Actually, the fan has one winding, but two resistors to create a "3-speed" fan. Apparently, a resistor or fuse in the resistor block opens up and now the only speed that works is "jet mode". But the module is not sold separately. The whole fan assembly needs to be replaced.


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## jblackburn (Apr 14, 2012)

ChevyGuy said:


> Actually, the fan has one winding, but two resistors to create a "3-speed" fan. Apparently, a resistor or fuse in the resistor block opens up and now the only speed that works is "jet mode". But the module is not sold separately. The whole fan assembly needs to be replaced.


That makes more sense. My old car had two separate stages for the fan motor, but I was unsure as to how the Cruze got 3 speeds out of it. I have seen it kick up to that medium speed when the AC is first turned on on a hot day.


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## Chevy Customer Care (Oct 29, 2011)

Themaverickdude said:


> How should I go about fixing this? Could a common mechanic check and fix that problem or do I need to take it to the dealership?


Hello Themaverickdude,

Sorry to hear about this air conditioning concern with your Cruze. I'd be happy to assist in scheduling you a service appointment at your GM dealership to get this checked out. Please send a private message with your VIN, full contact information, current mileage, and your preferred dealership to move forward.

Thanks!

Chelsea D.
Chevrolet Customer Care


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## Philb (Jun 18, 2016)

Themaverickdude said:


> How should I go about fixing this? Could a common mechanic check and fix that problem or do I need to take it to the dealership?


A "good" mechanic should be able to diagnose and repair your problem. Operative word being good. I have a mechanic who has been reliable about diagnosing and repairing problems and doing it right the first time. If you don't have someone like that then the dealer may be the best solution. Only you can make that determination. I hope everything works out for you and keep us informed as to the outcome.


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