A coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.
Car Problem Reports
Mercedes-Benz E420 Radiators Break Due to Degradation of the Plastic Tanks and Fittings
Mercedes-Benz E420 Problem
Average Mileage: 175,168 mi (130,000 mi - 210,673 mi)
Visitor, 1997 Mercedes-Benz E420, 173,000 mi
Radiator became leaky after radiator hoses and heater/bypass hoses had been replaced.
Visitor, 1997 Mercedes-Benz E420, 130,000 mi
coolent level always says low car over heats in park and wen a/c is running
Visitor, 1994 Mercedes-Benz E420, 187,000 mi
i dnt c no leak bat i always add coolant every 2 weeks