# buzzing niose under hood



## ChevyCruzeLTZ (Apr 7, 2011)

Got any more info for us? When does it happen? Engine on or off? How loud is it, when does it go away?


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## lilmrsyeti (Mar 3, 2012)

Mines not a buzzing sounds, but a Tone sound. After I shut the car off..you can here this tone..I thought at first it was coming from inside the Cabin, until one day I got out quick enough and it was actually coming from under the hood. Doesn't last long...maybe less than 30 seconds...have always wondered what that was??


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## mido (Sep 28, 2011)

this is the gaz pump i guess


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## Chevy Customer Care (Oct 29, 2011)

bhdq said:


> I am hearing a buzzing sound after driving when i pull in and park in my garage . What is this buzzing sound. this ia a 1.4 turbo




bhdq,
If you feel that you are hearing a sound that is not normal I would suggest that you take your vehicle into your local dealership and have them look into this for you. They are in the best position to diagnose your vehicle for you. If you have any further questions please feel free to contact me.
Thank you,
Stacy Chevrolet Customer Service


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## 115 (Nov 12, 2010)

Does the buzz happen when you apply the brakes? Is so then it's normal but if you're not sure then go to a dealership.


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## mcg75 (Mar 5, 2012)

bojangles said:


> Does the buzz happen when you apply the brakes? Is so then it's normal but if you're not sure then go to a dealership.


I'm hearing this and thought it was rather odd but normal as well.


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## jdubb11 (Mar 14, 2012)

ive heard it as well. seems to be after the car has been off for a couple mins even. i was playin with the radio after turning car off and it was about 20sec "buzz" sound


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## H3LLON3ARTH (Dec 16, 2011)

From my understsnding its the abs system doin a self check but I may be wrong I hear it all the time

h3llion


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## SeanM402 (Aug 8, 2011)

I have also heard the "tone" sound like lilmrsyeti has heard. It is not a "buzz" sound but sounds like a tone you would hear during a hearing test. I have heard it just walking past my car in the garage even though it hadn't been started at all that day.


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## ecw73 (Mar 17, 2011)

I hear a tone like noise when I step on the brakes, but only when in reverse. Anyone else hear that? Is it normal?


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## lilmrsyeti (Mar 3, 2012)

SeanM402 said:


> I have also heard the "tone" sound like lilmrsyeti has heard. It is not a "buzz" sound but sounds like a tone you would hear during a hearing test. I have heard it just walking past my car in the garage even though it hadn't been started at all that day.



Yesterday I went out to my car to put the sun visor in the window...I didn't start the car, just opened the door, put the sun visor up then got out...as soon as I shut the door, I heard that Tone again coming from under the hood...still wondering what that is??


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## Chevy Customer Care (Oct 29, 2011)

ecw73 said:


> I hear a tone like noise when I step on the brakes, but only when in reverse. Anyone else hear that? Is it normal?


Stacy or I would be happy to look into this for you with the last eight of your VIN. Please feel free to contact us privately for more assistance. Thank you. 

Tricia, Chevrolet Customer Service (filling in for Stacy).


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## DCfromSTP (Mar 26, 2012)

ecw73 said:


> I hear a tone like noise when I step on the brakes, but only when in reverse. Anyone else hear that? Is it normal?


I heard this on mine the other day for the first time. I cant remember if I was in reverse tho... think it was in park. Every time I pressed on the brake I would hear a tone. Let me know what you find out.


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## Chevy Customer Care (Oct 29, 2011)

DCfromSTP said:


> I heard this on mine the other day for the first time. I cant remember if I was in reverse tho... think it was in park. Every time I pressed on the brake I would hear a tone. Let me know what you find out.




DCfromSTP,
I would suggest that you take your Cruze into your dealership and have them look into this for you. They are in the best position to diagnose your vehicle for you. Please keep me posted on this. If you have any further questions please feel free to contact me.
Thank you,
Stacy Chevrolet Customer Service


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## DCfromSTP (Mar 26, 2012)

Chevy Customer Service said:


> DCfromSTP,
> I would suggest that you take your Cruze into your dealership and have them look into this for you. They are in the best position to diagnose your vehicle for you. Please keep me posted on this. If you have any further questions please feel free to contact me.
> Thank you,
> Stacy Chevrolet Customer Service


I have to go in for a oil change soon so i will have them take a look at it and post hear what i find out. Thanks


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## jlove (May 16, 2012)

I heard the sound too, so I mentioned it to the dealer when I took it in for a recall item. They were aware of it and said that there was an expansion value that they had to put in which will stop the sound... They put it in and voila!! I STILL hear the sound!! So did they.


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## TwinStealth (Aug 12, 2012)

I just purchased my Cruze but worked at the Chevrolet dealer I bought my car from. After I purchased the car I talked to many techs that I am still friends with at that dealer and they told me they have been hearing this a lot "a weird noise at idle with the a/c off" and they told me its being caused by the a/c compressor. I'm not sure if this is the same sound but it very well could be and if it is most of the dealers are aware of this and ready for it. Hope this helps.


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## Skipper (Jul 5, 2013)

2012 Chevy Cruze 1.4L with turbo
Buzzing noise under hood after car shut off and key removed.
Could this be associated with the turbo?
My dealership has no clue what it is.
Anybody able to solve this problem?


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## Merc6 (Jun 8, 2013)

Was gonna ask did you all have the A/C on when you shut the car off and was it only automatic trans vehicles? My car doesn't do it but at random OnStar will come on and ask an empty cabin if they want to test out the turn by turn feature.


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## Cruze2.0Diesel (Jun 30, 2013)

I'm able to here a hum on my diesel anytime you open a door or shut the car off, it doesn't last long. I personally think it's normal operation and the noise is the electric power steering rack and pinion motor. Obviously I'm not able to hear yours or anyone else's noise. I am not willing to start pulling relay (#7 clicks on when I open the door) and unplugging electric rack and pinion steering motors on my brand new car, especially when I think this is normal operation. The dealership should have no problem tracking down a noise that happens regularly, it took me less than 5 min to track down the hum in mine.


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## AVCruze12 (Feb 27, 2013)

Supposedly as per my post in another thread on here it is the A/C , either some kind of solenoid or pressure bleeding down...Mine has done it once so far and if you were to turn the key on then back off it disappears.

http://www.youtube.com/watch?v=vVMg0Ovpohw


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## Cruze2.0Diesel (Jun 30, 2013)

AVCruze12 said:


> Supposedly as per my post in another thread on here it is the A/C , either some kind of solenoid or pressure bleeding down...Mine has done it once so far and if you were to turn the key on then back off it disappears.
> 
> Cruze noise - YouTube


 Not the same thing I hear on mine and it does sound like it's coming from the A/C compressor. I don't think it's pressure equalization because of the sound and the fact it disappears when you turn the key on and off. If it was doing it on mine I would pull the A/C compressor clutch relay and see if it goes away, just long enough to verify your suspicions.


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## Aussie (Sep 16, 2012)

Cruze2.0Diesel said:


> I'm able to here a hum on my diesel anytime you open a door or shut the car off, it doesn't last long. I personally think it's normal operation and the noise is the electric power steering rack and pinion motor. Obviously I'm not able to hear yours or anyone else's noise. I am not willing to start pulling relay (#7 clicks on when I open the door) and unplugging electric rack and pinion steering motors on my brand new car, especially when I think this is normal operation. The dealership should have no problem tracking down a noise that happens regularly, it took me less than 5 min to track down the hum in mine.


My diesel does it too and I have regular power steering. It even starts up when the doors are unlocked in the morning, never caused any problems so I ignore it. Seems quite common there is another post about it on Cruzetalk.


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## Cruze2.0Diesel (Jun 30, 2013)

My hum is nothing like the video on my diesel and it doesn't last long at all, maybe 30 seconds. His noise is coming from the compressor. I looked at the type of A/C compressor that is installed on the cruze. It is a variable displacement compressor, I think the noise is coming from the electrical motor that adjusts compressor displacement. It is not the sound of equalization between the high and low side, this is electrical noise and I don't think it should continue to try and adjust the compressor after engine shut down. I don't think it's a compressor issue, probably a control module issue. I would bring it in to the dealer for sure.


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## foxdude0486 (Jun 19, 2013)

That buzz/tone sounds very audible. I've not heard anything like it, and I've definitely popped my hood a few times right after turning off the car just to poke around some since it's new and a little different than my old car.


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## Skipper (Jul 5, 2013)

It is intermittent and seems to happen when the A/C is on or off. It's an automatic.
The performance is not affected and runs great otherwise.
I'm surprised with the number of people having the same problem that Chevy has not looked into the problem.


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## cecaa850 (Apr 9, 2012)

Vacuum pump?


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## CruzeTD (Jun 1, 2013)

I have a 14' diesel and it makes the same sound as the two clips people have posted. I don't hear it all the time just occasionally. Guess I will have to start paying attention more. 


Sent from AutoGuide.com Free App


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## Bohdan (Apr 28, 2012)

Mine seems to come and go and lasts only for 5 seconds and not all the time. This happens only when it is very hot outside and the Climate Control is being used all the time.


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## Cruze2.0Diesel (Jun 30, 2013)

The wobble plate in the compressor changes it's pitch which changes piston stoke (variable displacement). The high side pressure correlates to ambient temperature and so does the compressor wobble plate angle. So we have an intermittent noise based on ambient temperature. I have never had that noise, more likely because I have a turbo I always shut off the A/C and let the engine idle for 1-2 min depending on how much I feel I should let the turbo cool. I suspect the electric motor that changes wobble plate angle is trying to adjust as the pressures equalize. I know this is all just an educated guess but I haven't seen any other explanation that makes sense.


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## goinovr (May 6, 2013)

There are mixed reasons that could be causing the problem. I get the tone even when I don't run the A/C. Apparently there is a cooling system for the turbo that kicks on. 

http://www.cruzetalk.com/forum/10-e...4-buzzing-sound-after-turning-off-car-17.html



ChevyMgr said:


> I was told that if the blower is turned off and the key is turned off within 10 seconds and the pulse width of the solenoid inside of the a/c compressor is between 45-58%, it can cause a buzz like a reed for 10 seconds to 10 minutes. Ponder that one. :wacko:


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## Cruze2.0Diesel (Jun 30, 2013)

The A/C will run with defrost, and the sounds could be different than that in the video causing different opinions and diagnosis. Like I said mine hums but it is quite and it is on the firewall side of the engine down by the electric steering gear. I haven't seen anything in the service manual about an electric water pump and I don't see one in the exploded view of the cooling system? The link to that post by ChevyMgr makes perfect sense with what I was saying, thanks for the link, seems Chevy is working the problem out already. Just get it in for the update program for the control module, problem solved.


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## Stingray1974 (Mar 14, 2012)

*Buzz under hood / other problems*

My 2015 Cruze Eco buzzes when shut off. It Buzzes for about 5 minutes and then gets loud for about a minute. If I open a door after it stops, then it will buzz load again. My 2015 also uses Antifreeze like my 2012 did and it is getting worse -about 8 oz. since last oil change. Sometimes temperature goes over 236 deg. F. but dealer or GM just says this is normal and cannot say how cooling system is supposed to work. My steering sticks when going down the highway when you don't move it for a bit. When you move it this sticking causes it to jerk which would be bad when roads are icy. My car does not get claimed mileage as my 2012 did. When I drive it it will stay on high charge 14.7 volts for over 250 miles which is part of mileage problem. My Navigation locks up and sometimes shows me on side roads that I am not on. Dealer's recommendation is to use my smartphone.Seems like more problems on this last model year than were in previous models. Very poor job of reacting to problems and fixing them by GM. I guess when GM always just says there is no problem there is nothing for them to follow up on.


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## ChevyGuy (Dec 13, 2014)

Stingray1974, sounds like you need to visit another dealer.


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## 4rent2u (Mar 30, 2013)

I've got a '12 Cruze LT RS with a stick shift and it has the buzzing noise occasionally.  My dealership told me it needed a software update to cure that, so $45 later...... yep.... I've still got the buzzing going on occasionally. Thanks local Chevy dealer! Aside from the very minor annoyance that is the buzzing noise, my car is great. It's fun to drive and gets great fuel mileage.


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