Steamed on the freeway. Heater Core?
 

Steaming radiator fluid has filled the interior of my 1992 300E 2.6
Nothing leaking under the hood. Steam is mostly coming from vents on dash.
I've just replaced the radiator and now I suspect a heater core.
Any advice or link to more info on this job.
Thanks

My experience with american cars would tell me you are right.

Heater core.

Your earlier post described replacing the radiator and therefore closing
any escape routes for pressure.

Check the manual or maybe mercedes.braingears.com for the online manual.

Heater cores are not too bad. Just some time and lots of removing parts
to get at the thing.

Check the heater core hoses at the firewall, make sure one of those didn't rupture. If it is the hearter core, expect to gut the dash. Seems these cars are built around the evaporator and heater core.