Vibration at Lower RPMs

[blk09rollale]

I recently had this. Especially when cruising at 30-40mph and during engine braking. Thought it could be the serpentine belt already going bad. I noticed it after I had driven thru some deep snow.
Upon inspection the belt looked perfect but one of the plastic covers in the undercarriage had come loose. After resecuring the vibration is gone. Thank god it was an easy fix.
Thought I would post since many of you are dropped on lower suspension and/or live in snow plagued areas. Check your undercarriage. Those plastic covers come loose very easily.

[creslayer]

when im in a stop position like waiting at the lights my RPM drops 200 and my car shakes, i turn my headlights on and it stops..... but only when my lights are on