When I first start my truck there is a knocking noise. I know this has been addressed before but don't know what everybody has come up with. Please keep in mind that it was doing it before any mods have been done to the engine. I just always thought it was a lifter. It goes away after it warms up. Doesn't seem to knock very long really. Anybody know about this?

 

its carbon build up on top of the pistons,most likely....no long term ills from it.

 

Argon, would you recommend anything other then the gm upper engine cleaner stuff? Like something that doesnt take as long, Like Spraying water into the intake.

 

my 1998 does the same thing, it knocks when cold but when it is warm it sounds fine. I haven't messed with anything and figure if the moter blows up I can get a brand new one for $1600

 

Do not spray water into youre intake!!!!!!!! unless you remove it and let it dry.