rocker noise

[jonnyh]

My 03 Duramax develops what I think is rocker noise at around 85mph. If I speed up or lsow down the noise goes away. Several people I have spoken to said they have the same noise. Does anybody know what it is or have a fix?

[More Power]

In general, a mechanical problem like a rocker issue doesn't go away. It's there all the time, and may be more noticeable at specific rpms.

You may be hearing a change in pilot injection. The sound produced by this varies a little between trucks and programming, but it sounds like a rattle (or tap) at higher rpms under load.

MP

[jonnyh]

That oculd be what I am hearing. It does sound like a rattle and goes away with additional throttle input. If it were valve float I think the additional throttle would make it worse not clear it up. Thanks for the input.