The V-8 Mercedes of the 90s all end up needing the power steering pump resealed. The groan is probably from low power steering fluid allowing air to be sucked into the system. The best guess that I have on the high pitched whine is that you are hearing the alternator charging at a high rate. This could be caused by seasonal loads with your heater, rear defrost, seat heaters etc.. You could also have a weak battery that is requiring recharge on cold start. I hope this helps.