Just got my wagon back after a $2,700 repair bill (wiring harness, acccelerator cable, trans svc, etc all at a top notch Benz Dealer.). One of the last things I was told "the vehicle is overheating, your radiator is plugged, $600 more..."

This is my fifth Benz I've done this before, so I ordered a radiator and new hoses and in less than two hours and for under $200 replaced same.

Started car up...no leaks, tight all around... drove out and the temp shot right back up to 120 and only when I turned on the internal heater did the temp come down to about 100. Drove around the neighborhood and same thing, always shooting up towards the 120 mark.

Both fans are working fine. What could I be missing?

Danke!