Sorry to hear about this nightmare .... I was wondering if when it gets hot is the radiator hot all over as well?
Additionally, this makes me think there is something wrong with the thermostat. Are you sure of it?
Hang in there and keep us posted.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)