My car is making a Vibration/Humming sound near pulleys/belts

What is your question?

Recently after my coolant was draining rather quickly and my engine light came on I replaced my heater core.. due to it being clogged.. but ever since my car has been vibrating slightly and making a humming sound coming from near the front of the car and somewhere underneath or near the AC Compressor.. and my car has been hitting 210 rather frequently and this only happens while Idle'ing or driving in LOW rpm's

What makes this problem better or worse?

Higher Gears

How long has your 2014 Volkswagen Passat had this problem?

Week