My engine developed a tapping sound about 10,000 miles into owning it. Wasnat throwing any codes and it wasnat extremely noticeable. I have been a mechanic for 20 years and knew something was wrong. Brought it to the dealership. They refused to investigate further due to no codes being on the computer fast-forward to 74000 miles on the vehicle. The engine locks up and leaves me stranded six hours away from home. Yes, the oil was changed religiously throughout the engineas life, and all service was done through the dealership. I went back and forth with GM for weeks and they still refused to replace the engine on their dime. I was forced to come out of pocket 13000 dollars to replace the engine. Due to the warranty being out by 14000 miles. GM COULDNaT EVEN TELL ME WHY IT EXPLODED AND COULD NOT ASSURE ME THAT THE SAME ISSUE WOULD NOT HAPPEN TO MY REPLACEMENT ENGINE. 2nd engine started to DO THE SAME THING AFTER 8000 MILES AND THE SAME THING HAPPENED AT THE DEALERSHIP. THEY REFUSE TO DO ANYTHING BECAUSE THERE WAS NO CODES. NOW I HAVE 30,000 MILES ON THE SECOND ENGINE AND I KNOW WITHIN THE NEXT FEW MONTHS ITaS GOING TO DO THE SAME EXACT THING BY THE WAY ITaS RUNNING. Iam disgusted. GM has personally put me in excessive financial strain and caused me serious anxiety. And now Iam driving around a ticking time bomb with no resolution.