Loud Engine Noise problems of the 2008 GMC Acadia

The contact owns a 2008 GMC Acadia. The contact stated that while driving at various speeds, an abnormal noise appeared underneath the front driver's side hood. No warning light illuminated. The vehicle was taken to an independent mechanic where it was diagnosed that the engine was consuming an excessive amount of oil. No leaks were present. The vehicle received an oil change however, the failure recurred. The dealer was contacted. The manufacturer was notified of the failure and a case was filed. The failure mileage was approximately 153,245.

My family and I were driving out of town and then started to feel the car jerk at times and then out of no were it said stability traction control off and reduced power of engine and then engine started to make a terrible noise and shacking like it was going to give out. I could barely pull over. I have taken it several times in to get checked for the stability and they can never find anything wrong and they say its one thing and all I seem to do is pay for something that doesn't need to be fixed. This same issue has happened 3 times since then.

While out shopping with my children when I attempted to turn off the vehicle to depart for the mall, the ignition turned to the off position, I removed the key but the car remained on. I then noticed that the check engine light illuminated. Shortly after, the car began shaking violently; I assume as it was attempting to shut off. I inserted the key, shifted into to reverse, pulled out of spot and then back in again. Proceeded to turn vehicle off and again, key removed but car still running. Again the violent shaking along with loud noises began. Afraid, I instructed my children to leave the vehicle. We got a comfortable distance from the vehicle and continued to watch. It took 25 minutes for the car to shut totally down. When I went back to the car, as I opened the door, I noticed the warning sound as if the key was in the ignition and also although the entire dash was off, the check engine light was still on, (im not sure how since the car was "off" and no key inserted). I drove the car home and the same thing happened when exiting the vehicle. The car remained on, began shaking and the check engine light also stayed on after the car was totally shut down. Very scary experience. I noticed via the internet that this was not a new issue. I wonder why gm would not have corrected this problem with its vehicles by now. I am a single parent and my teenage daughter sometimes has to run errands for me in this vehicle, I would hate for this to happen when im not with her. . . . Its was frightening enough for me!.