Have an 03 D/A,78000 mi. Around 2100-2300 rpm it sounds like a sticky lifter on a gas motor when accelerating fairly hard. Have been told this is due to pilot injection but thought that did not start till 2500 or higher. Took in to have checked out and of course was told that nothing unusual and was given gm article on pilot inj and typewriter tick. Have only had this truck for about a month and has been this way since bought it. Does not run rough or start hard or smoke at all. Should I believe what was told??? Had a powerstroke before this and am not used to this quiet so maybe hear normal dmax noise???? Any thoughts appreciated. thanks guys.

sounds normal to me. welcome to the site. and congrats on buying the duramax and not another power -:t :D ):h

This morning hooked the edge back up and set on level 1 also changed the fuel filter and the noise seems to have quieted down some. Maybe should have done each of these one at a time to see which helped. Thanks.:)

The pilot injection also shuts off when you exceed a certain fuel flow - so it can shut off at less than the specified rpm value. I don't think you have anything to worry about.

- jeff

fieldoc
My truck has done this since it was new, sounds just like a loose lifter on one cylinder. The noise comes on at about 1800 rpm when under load (pulling trailer). It's not the pilot injection shutoff which happens at about 2400 rpm on my truck. I've seen several other posts about this same type of noise, however no one really seems to know what it is. All I know is - it's not the pilot injection turning off or the tick some people hear at idle.