Engine noise
 

I have an 03 2500HD with the 6.0l. I bought it with 80,000 on it and now has 148,000. It has always had this noise since I bought it. If I am driving in town and am on a street that has stop signs every block I hear it the most with the windows down. I take off from the stop sign and then at about half block I left off and then I hear the noise. It sounds like lifter noise or maybe piston slap? Not really sure which or what it is. It has never got any worse but I am curious as to what it might be.

Re: Engine noise
 

I have a 2003 1500hd with a 6.0L, and have heard from a few people that piston slap is normal on these trucks until they warm up. I haven't noticed any motor noises with my truck yet and it has 160k miles and counting. Maybe it can help better diagnose the issue.

Re: Engine noise
 

I hear this noise whether its warmed up or not but only like I described it when going city block to block and only when letting off the gas. Piston slap is probably what it is though.