My commute is only 2.5 miles, and takes roughly 6-7 minutes. While I do start to get warm-ish air by the time I get to work, it never gets hot, though the temp gauge gets to 80C. The ambient temperature is only 50degF.

It is, however, slightly warmer than the temperature of the air coming off the radiator from the fan (which isn't warm at all).

Yesterday when I drove it around for around 20 minutes, I put it on defrost and got hot air immediately, even at idle. When I pulled the plug to the monovalve, I got strong heat at every temp/vent setting (A/C is out as are some vent pods).

Since the heat comes directly off of the block, I would expect it to be that hot when it goes through the heater core. Is that not the case or is my commute simply too short?

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A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.