IN the winter that type of build-up isn't abnormal.. Driving for 40-50 miles on a freeway at speed should elimate that build-up.

Heat in the engine will evaporate the WATER that condenses in that filler neck.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator