300E 24 Automatic.
 

Hi all. I have a 300E 24 Automatic which I purchased last November which developed a running problem which wasn't finally solved until February, 2006 by replacement of the distributor and rotor arm.
Since that time it has run perfectly until this week when the lumpy running etc reappeared.
Having looked at the dissy again this weekend we discovered it was very damp and the contacts going green.
I have two questions basically:
1/ What makes the dissy damp as it is well sealed.
2/ How can it be rectified without constant removal etc.
Incidentally this problem was one that bugged me with my 190E 2.6 too and one of the reasons I lost confidence in the model
and bought the 300.
My husband runs a 190E 2.00 and has never had this problem even though his car stands round most of the time idle.
I would appreciate any ideas on this with winter coming on soon.