i just bought my very first mercedes (actually, first car of any kind) after searching long and hard for exactly what i wanted, so first i'll request a moment of silence for my bank account followed by a round of applause for my purchase...

anyway, the car shakes pretty intensely when it idles, but when it reaches 800-900 RPM it's ok. any ideas as to what could be causing this? my friend suggested that it might be related to the idle-control valve, but he's unsure if these cars have one. i obviously have no clue either way.

has anyone experienced this? the shaking is pretty bad and i'm hoping it's not symptomatic of a very expensive problem...

thanks!!