Ive been noticing that when I start up my truck, it knocks, :: clenk clenk clenk, clunk::: then it gets a little quieter as it warms up, but still noticable?

I know its a known problem for GM's newest truck motors but, does yours do it as well?

I think its time for me to get an LS6

 

OH, and my dad has a GMC crewcab HD w/ the 6.0...

sounds like a ficken deisel knocks horribly.

 

Its pretty common it our trucks. Some do it worse than others. You might want to check this out.
http://www.pistonslap.com/

 

maybe i should hook up a 300 shot of nitrous, blow up my motor, disconnect the nitrous, and get a new motor? lol..jk.

Im not too worried about it, it just sounds like its hurting somthing.. but it nothing happens great, and if it blows a hole through my hood.. well by gosh thats great too!

 

The way you said that made me laugh my a** off!
I have a 2002 LS1 Camaro at the dealer right now being rebuilt under warranty because it sounds like a diesel! My 2003 Silverado 5.3 also knocks but not even close to what the Camaro does. You can hear it on start up but you have to listen hard and sometimes pop the hood but it is there and even on hot start up it knocks for a few seconds then goes away.

 

Mine doesnt knock on start up. But, when it warms up it ticks. Sounds like too much valve lash maybe?? Anyone else start ok, but after its warmed up it ticks??

 

I cant tell the story with just graemlins:

4.8 LS6

 

 

My buddy's 02 6.0 HD has crazy piston slap on startup.

 

Same here. My 01 and 02 don't knock at start up but once they worm up, they will tick quaetly.