Hi guys,
It's been a while since I've been on here. Recently I did some repairs to the truck which consisted of knock sensors, knock sensor harness, valley pan and gasket, oil pressure sending unit, valve cover gaskets, intake manifold gasket and cleaned the fuel injectors. Before this work there was a very noticeable ping or rattle sound when accelerating and thought it was because of the faulty knock sensor. While doing this work I found that the faulty sensor was very rusty and the tip for the connector was completely broken off.
All GM parts were used and the work went very good. I did the RTV seal around the knock sensor boots as well to prevent moisture from entering. With everything there replaced, I am still getting the pinging sound under light load conditions and with the scanner connected there's no KR when the sound is present or any other time. It's happening under 2,000 rpms and throttle % around 25-35%. Above that is fine and if running WOT there's no sound either. Could this be deposits built up in the cylinders or on the valves? There's also no trouble codes anymore for the knock sensors.