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post #1 of 8 (permalink) Old 01-13-2014, 08:09 PM Thread Starter
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RPM Jumping.

Had my Cobalt for a few months now, and I noticed that when I'm going at a steady speed on the streets (between 35-40 mph usually) the engine revs as if I am giving it gas and letting it off rapidly and the tachometer jumps between 2000 and 2500 RPMs. It's hard to explain but here is a video of another vehicle (a Malibu of the same year) doing the same thing, but at a different speed.

I'm driving an automatic, if that changes anything.

Thanks!
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post #2 of 8 (permalink) Old 01-13-2014, 08:38 PM
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Interesting. Is it coding?

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post #3 of 8 (permalink) Old 01-13-2014, 08:55 PM
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You need a new valve body and valves. One of the valves were probably installed upside down and the tcm will need to be reprogram.

Let me find you a link to the thread about it

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---------- Post added at 08:55 PM ---------- Previous post was at 08:53 PM ----------

https://www.yourcobalt.com/forums/sho...d.php?p=579407

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post #4 of 8 (permalink) Old 01-13-2014, 08:58 PM Thread Starter
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I still have the powertrain warranty on the vehicle. Would this be covered service?

And no, its not throwing any codes of any sort. Other than this issue, the car is running perfectly.
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post #5 of 8 (permalink) Old 01-14-2014, 03:39 AM
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Yes, this would be covered under extended powertrain warranty.

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post #6 of 8 (permalink) Old 01-14-2014, 06:40 AM
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Kilokk,

Have you been able to reach out to your Chevrolet dealership? Let me know if you need any assistance.

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Have you checked into Chevrolet Owner Center? You can maintain service history, check on warranty or recall information, and more. Visit my.chevrolet.com!
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post #7 of 8 (permalink) Old 01-15-2014, 08:08 PM Thread Starter
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Thanks for the help everyone!
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post #8 of 8 (permalink) Old 01-16-2014, 09:39 AM
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Yup same thing happened to me valve body replacement and ECM reprogram covered under 100k mile warranty

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