so I took my 2010 mcs in for service work a couple weeks ago and had my timing chain and guides replaced. it was stretched to the point that It was a little out of time and not idling properly and typical death rattle. there were also a few other things that needed to be fixed along with that. I had my valves blasted at 52000 miles and am now at 78k. The service technician told me that the valves needed cleaning again. due to the engine being out of time the engine was consuming more oil than it should, and made the carbon build up situation worse than it would have been at this point. if this was due to the timing chain issue shouldn't it be covered under warranty as well? they also told me that there was ice build up on the throttle body. they charged me for diagnostics because they called it regular wear and tear. when is it normal to have ice build up on a throttle body. that isn't normal for any vehicle.