From time to time, when I start my truck it is very loud. This is very random and I haven't been able to link it with a certain condition, temp, etc. It's not struggling or performing poorly just very loud, cold days, hot days, doesn't matter. Someone please tell me that this is an engineered function of the engine and not a problem. Thanks for any input, I know this is the 6.2 forum so but for anyone that wants to ask...yes it is a 6.2 2011 xlt.