If it's anthing like my 124 there is a bracket that holds the pulley that is bolted to the block. It contains the bearing on wich the pulley is mounted (4 bolts) which, if it goes bad, requires replaceing the whole bracket.
If this is the case and it is on its way out it could go at any time (movement is the begining of the end)... make preperations to get the part as the car is undriveable without it.
Again this is the scenario on a 124 car so make sure it applys to your 210 before you take my advise.
