So I am taking the car home last night and on my way home about 3 blocks away the rear drivers coilover start making this pulsing noise, it gets progressively more rapid, so I come to a stop but it continues always getting more intense pulsation.

By the time I get home and open up the garage it has completely gone away. It went almost like a harmonic fork you hit it it vibrates progressively more and then progressively less.

Any ideas?

 

pillowball mount on top ---> loose nut holding the assembly together?

lugnuts tight?

 

Mods please delete this thread. The noise came and went as I switched the ignition on and off, from what I know about cars there is no electrical current relation to suspension parts, must be a busted speaker in the back.