First, in the 190E, no heated air is ever passed thru the center console vents, only the left and right side, footwells and up to the windscreen, that's just how the white lab coats in Stuttgart designed it. Only "unheated" air (fresh and a/c) will ever come through those center vents.
As for your engine temp, you should have a look at the auxillar fan while the car is idling in the driveway. It should automatically spin on and off from time to time, to help regulate the coolant temp while not moving. If it does not move, you either have a failed/disconnected temperature sensor at the front of the engine block, or the fan and/or it's magnetic clutch has failed.