Noise in Vortec Motor 5.3 2007, Silverado.

I have a 2007 Silverado truck. For a few days a fault has been presented. After starting and moving between 1200 and 1500 rpm a noise appears in the engine (similar to a wake). By removing the accelerator's foot, the noise disappears and eventually reappears depending on the effort that the route demands. It is important to note that being parked no noise. It only appears in the RPM interval that indicates them. This is a Vortec 5.3 2007 engine. What do you recommend? Thanks for your help.

That noise you say gives a can when you look for it because it can be from the chains, the pine nuts tenders of the distribution, badly calibrated valves, play in the cams with respect to their vanadas, play in the piston pins, and everything sounds the same in that engine because everything is metallic, it is only heard where it affects that it is usually in the valve cover.