My new GMC Sierra has an annoying miss idling

[Texastruckowner]

I bought my brand-new GMC Sierra last month. It is a 2014. We have noticed when it is idling that it has a miss in it. It is like in annoying intermittent vibration and at times it even feels like the truck is going to die. I have also noticed one driving that it doesn't have the kind of power that I feel it should have. The power thing is not all the time, just sometimes. Also the battery gauge can be anywhere from 9 to 14 depending on I don't know what. Anyway, it is a six cylinder and when I called the service department they said that there is no need to bring it in if there is not a check engine light on. I just hate the way it feels idling and I Love the truck, so I want it to work perfectly. I am not sure if it is normal, or if there is something wrong with it. The service department asked like I am crazy. Although they have not looked at it.

[TJay74]

Check the spark plug wires. There were some cases of the wires not being on the coil or the plugs all the way causing issues.

[Carder09]

Your voltage shold be correct due to the voltage regulator for saving gad, supposedly. I would drive directly to the dealer then talk. That way, you can talk to a service guy and hopefully he will run out to the truck with you and take a quick look.

[bdbake01]

Good advice here. I've noticed a bit of a stumble at times myself, but if it's a sharp miss or loss of power, check the plug wires. I had one off from the factory.

 

As for the voltage, looks odd but perfectly normal.