# My 2011 is making a pulsing sound



## VanessaMoran (Oct 17, 2015)

My 2011 LTZ recently (about 2 weeks ago) started making a pulsing sound when I'm stopped at a red light or parked. It sounds like the car just ran a marathon and its heart is beating a million miles per hour. I took a video of the sound that I'm posting as well. 



 Has anyone had this issue before?


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## ChevyGuy (Dec 13, 2014)

I'm thinking that sounds about right "beat" for the serpentine belt. Perhaps a contaminated area or a slick spot on it.

The other thought is that hasn't quite made it to "chirp" yet. So I'd check for loose spark plugs as well as pull the dipstick to see if the sound goes away.


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## VanessaMoran (Oct 17, 2015)

I'm gonna change the spark plugs and air filter tomorrow. Thank you for the idea of the serpentine belt. I will also check that out.


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## spacedout (Dec 7, 2010)

Isn't this idle pulsing typically a sign of a vacuum leak / bad PCV valve cover?


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## ChevyGuy (Dec 13, 2014)

spacedout said:


> Isn't this idle pulsing typically a sign of a vacuum leak / bad PCV valve cover?


Possible. I don't remember seeing reports like that, but I could have missed them. I thought the symptom was rough idle. Or are you thinking about the one that pressurizes the engine and makes the seals chirp?


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## spacedout (Dec 7, 2010)

ChevyGuy said:


> Possible. I don't remember seeing reports like that, but I could have missed them. I thought the symptom was rough idle.


The pulsing idle shown in the video above is exactly what has been shown in previous threads, this is the rough idle so many speak of.


EDIT: I should add if you remove the ECOTEC engine cover can you hear air leaking from the round thing behind the oil fill on the drivers side? Some images on this thread might be helpful. 

http://www.cruzetalk.com/forum/129-...-replace-valve-camshaft-cover-1-4l-turbo.html


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## VanessaMoran (Oct 17, 2015)

Does anyone know where I can find a diagram of that vacuum lines? I haven't had any luck finding a manual online so I'm assuming they haven't released it yet. Thanks for the replies.


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## jsusanka (Jan 31, 2011)

Have had any ECU engine codes?


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## jsusanka (Jan 31, 2011)

I have a question does it stop when the a/c is on? I wonder if it could be a pulley somewhere?


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## jsusanka (Jan 31, 2011)

Has the OP found a solution to the problem? I am just curious and would be nice to know the solution.


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