My 81 wagon was my first MB... and first non intake heated air diesel ( Ford tractor )...
and this was before computer/internet/shopforum....
at 50 degree F my wagon did not want to start... even though everything else was fine.... and the Haynes manual does not mention this " continues to heat" tip....
That was when I broke out my MB manuals... as hard as they are to interpret and found that gem...no problems after that with starting...