Over the COVID break my Q50S sat and was only driven a few miles a week for 8-10 weeks. Since that break I now have a strange howling like noise coming from the engine. It is most pronouned at idle. It does not change if I shift throughin PRND or turn steering wheel. As I accelerate I can't tell if it goes away or is simply drown out in the engine noise. I have used a stethoscope to probe everything I can imagine and can't locate where it is coming from. Does anyone have any ideas what the cause could be. My guess is power steering pump or AC compressor but the stethoscope is quiet when I probe those.