Getting right to it, my 2014 LT RS (around 20, 000 mi) seems to have the classic chirping symptoms of a problem (dry?) with the (front?) crank shaft seal … more noticeable when the a/c is on, and continues chirping for 3-4 seconds after the engine is turned off.
Pull oil dipstick or open oil fill cap and the chirping stops. The oil is full ... no excess consumption. No CEL/codes.
I've only gotten this far thanks to other threads and your wise counsel. But, I still have these questions before going for service.
1) Is there a GM Service Bulletin specific to this problem? 2) Is this just an irritating chirp or can it lead to other problems down the road? 3) Should techs also check the valve cover/PCV diaphragm and PCV check valve in the intake manifold for possible impact when fixing the replacing crank shaft seal?