I think if you have a heater core problem, you will be smelling antifreeze in the car, like mine is doing.

I think you have a heater box door that is not opening. Could be something as simple as a vacuum line disconnected.

I'm preparing to tear into my 190E and replace the heater core. I have the new one ready to go.

Good luck with your project!

Bruce

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.