My 2006 Hyundai Sonata’s A/C has been making some noise over the past month or two. Sounds like marbles jumbling around. I assumed that it was possibly the bearings going bad in the Compressor and/or Clutch. Two days ago, I was driving when the car started to vibrate noticeably and I pulled over immediately. I thought I may have had a flat tire. No such luck. I then turned the A/C switch to Off and the vibration went away. When I turned the A/C switch On again, the engine started to rev-up and vibrate (obviously a strain on the engine). Since I’m getting cold air, I’m assuming that the clutch and compressor are working but not properly. I also noticed a strange smell that I’m not familiar with (but it’s not a rubber smell and the surpentine belt is not squealing). I’m going to put the car up on stands this weekend to view the operation of the clutch and compressor from underneath. Do you think the A/C compressor is seized up?