Cannot believe a one year old car needs the pistons and rings to be replaced!!! It started out as Onstar emailing a warning about an Emissions problem. We brought into the dealer and they quickly dismissed it as nothing to worry about, just a software update was required.

A few weeks later the Engine light would intermittently come on and the engine started to run rough at times. It progressively got worse. The car would totally shut down when in Auto Stop and the car would have to be completely shut down or "Rebooted" to get it going again.

A warning that the Traction Control wasn't working came on intermittently as well. I'm unsure if they are all related or not.

We decided to bring to another Dealership to have the issues diagnosed. They had the car for a couple of days and finally did a "Leak Down" test on the cylinder combustion chamber . They quickly realized there was a BIG problem and notified me the engine needed a rebuild replacing all the cylinders and rings.

They said the Rings and pistons were TERRIBLY & COMPLETELY CORRODED.

When I asked how that's possible in a one year old car with 26k miles, their answers were vague. They eluded to the fact it was from inferior quality gas. The car is designed to run on "Regular" gas, but you need to use a PREMIUM grade of regular - like BP or Sunnoco.

SERIOUSLY? Where does it say that in the user manual?? That's total B.S. Yes, and we all know when you need gas, you're going to make sure you seek out a PREMIUM gas station.

The good news is it was all covered under warranty, but if I had to make an educated guess, the issue is due to CHEAP INFERIOR parts and has nothing to do with the gas. I have read many complaints of cracked pistons on this forum. Coincidence ? HIGHLY DOUBTFUL!!!

Hopefully is you're reading this and are experiencing similar issues, especially a rough running engine and intermittent Check Engine light, you should have your dealer perform a "Leak Down" test.