I hate shops that take advantage of women. However, they are out there. As far as your problem, they make products to clean the carbon from the engine (inside). If they are correct, that should fix the problem. However, if you still have a valve ping, I would ask that they check the knock sensor. It is a sensor that changes the engine timing to the point right before the valves make noise. That way the engine is running most efficiently. If it is bad, it can cause the problem, and it is an emissions component. Therefore, it is covered for 5 years or 50K with a 0 deductable.
Listen, find a local shop that provides the service I suggested and try it. If that doesn't take care of it, then go back to the dealer and demand they fix the problem under warranty. Make sure to continue using the recommended octane fuel, and let me know if anyone gives you a hard time. I'll be glad to give you advice. Heck, one time I called the dealer for a customer and raised hell. They don't intimidate me and I let them know I understand cars and they can't fool me.
You take care and let me know how things go.
Tuesday, March 9th, 2010 AT 9:40 PM