06 rattle on cold start, and full throtal

[john hyduck]

I have a 06 with 1500 miles on it. I changed the oil at 500 miles, it was black, very dirty. I used rotella 15 w 40. I called the dealer and was told thats what they use. This early oil change came because of a cold start metalic tap. I am a corvette restoration tech, been in the bis for 13 years so i know the diference between normal and abnormal, on gass engins, deisel ? This sounds like a hidrolick lifter problem? I know that the older cummins have solid cams, do the 06's? Also i hear a rattle only at first second or so of full throtal, at low rpms aprox 1000. I dont realy have anything to compaire to. My old truck was a 01 with bully dog exhaust. so all rattles and taps were normal. Maby im just picky, but it just dont seem normal. Has any one ever had any thing like it hapen to them.

 

[DPKetchum]

Same kinda cam setup and lifters as your 01 was. Some minor differances of course. Being so quiet the new ones do make a rattle noise some times like spark knock in a gasser that you can hear. Factory oil fill is Valoline Premium Blue as good or better quality then the Rotella.