I have an 06 LLY and for the past week or so I've noticed a Knocking sound slightly loader than the normal diesel engine rattle that seems to be coming from the oil pan area. Does anyone have an idea of what this noise could be?
I have an 04 LB7 and just last month I heard sort of a knocking sound that became loader after a week. Worried, I removed the serp belt and listened. The knock disappeared. Now I knew the knock was not internal. Turned out to be the vacuum pump. (covered by warrentee)