2015 200c, 63,000 miles. Getting an intermittent squealing sound from front end, no rhyme or reason. Happens while moving, stopped, idling, brakes, in park. Doesn't seem related to steering left or right. Temperature is normal, air conditioning works fine (and I didn't hear the noise when I started and stopped the air). Any ideas? Early warning that water pump is going? No leaks though. Or bearings starting to go in a pulley?