I noticed that the LS1 seemed to be making more pinging noise in this warmer weather so I hooked up a scanner and sure enough there is knock retard showing up when I hear the pinging. So I ran some Seafoam through it yesterday. Good thing there was a little breeze blowing!
Clouds of white smoke started to fill the neighborhood. So I took it out for a high rpm drive to try and burn the stuff off. I think I had a mile long smoke trail all the way down my road. There must have been some serious buildup in the engine considering it only has 36K miles on it. I've heard about the LS1's pulling oil through the PCV and I'm wondering if this is what cause the problem. I've used the Seafoam and GM TEC and both seem to do a pretty good job at cleaning up the combustion chambers.