GH80,

I suspect that even if your V fan clutch were totally shot "IT" would stop
rotating within 1or2 rpm's.

?Could you be hearing the ELECTRIC fan(s) [in front of the Radiator/Condensor]?

Hint...Run the engine until hot , shut it off (BUT, first open the hood) and
listen to where the sound is coming from.

I am not conversant with the electric fan relay setup on this model(EVEN
though I own one)

BUT

Many of today's (a 12 year old 'Benz is so far advanced, technology speaking
that it qualifies)cars electric fans (accessory) will continue to spin until the
engine temps fall below a preset level.