last Friday sitting at stop light my 2015 LT1 C7 starts vibrating significantly. The Traction Control indicator comes on saying it's not engaged then the Engine Light comes on and dark smoke billowing out the Exhaust. I managed to pull into the nearest Parking Lot and got OnStar on and they ran diagnostic and the Code reported was P0301 indicating an Engine misfire in Cylinder 1. OnStar called my Dealer and reported the Diagnostic Error Code and other information. The Dealer had a Tow Truck out to bring it into the Shop.

They've had it since Friday and I have not heard anything other than a call on Saturday indicating they were running diagnostics and needed to wait for their "Head Mechanic" to come in Monday (today). Still waiting to hear from them.

Anyone else have this happen??? Only have 3,200 miles so I'm concerned it may be something major, I'm sure Warranty will cover if necessary but it still leaves me a bit concerned.....

 

Billowing smoke means a coolant or oil leak. You will likely get a new engine.

 

I am having a issue with my 2014 C7 with only 4088 miles on it, the local dealer can't solve a issue with a cylinder 7 misfire, the car has been to the shop three times, and now I'm being told that they are waiting on GM to tell them what to do next. The have changed spark plugs, coils, and ejectors.

 

Confirm the Dealer has applied all Software Updates as well.

 

Could be a lot of things, the dealer should figure it out and make it right.

Please update what happens!

 

Hello all, first & foremost - thank you all for the replies and PM's. You have all been very helpful.

I honestly thought I had posted what the Dealer found, but apparently not - ugh, Alzheimers.....

Bottom line the Dealer Service Dept. could not find the cause. BUT what they did impressed the sh*t outta me. They did all the Diagnostics and found no cause. Next they applied all Software Updates and replaced all the Cables. They also engaged Technicians from the Tonawanda Plant, which performed Remote Diagnostics while the Dealer Technicians Road Tested the Vehicle. At the end of the day they could not find the reason for the misfire and determined with the new cabling and software updates and also installing a new Engine Control Module I should not have any further issues.

So, to say they went over and above is a doesn't begin to describe the excellent service I received. Everything covered under Warranty and not one cent out of my pocket.

I should note - I just recently Traded the Car for a 2016, LT3 Z51 Daytona Sunrise Convertible w/Carbon Fiber Package. I DID NOT trade my 2015 LT1 Arctic White Coupe that had the misfire because of that issue - I simply should have bought the Convertible to begin with, I am extremely happy with my new 16 Z51 Convertible.

I have no doubt the 15 LT1 is enjoying a good life in a nice comfy Garage right now!

Again, thanks to all you offered advice - you Guys are the best!

 

I am having this exact problem now. Did you ever get your problem resolved and how did they resolve it?

 

I see it now. My bad

 

How was this ever resolved having exact problem down to the 7 cylinder?