"Just to confirm, by silencing the nailing via loosening the injector line, I am eliminating a crappy valve job? " (adjustment) .

No, it's just the first step in detecting where the problem possibly lies .

Just do this (swap the injectors) and see what happens ~ if the nailing follows the injector to a different cylinder, this tells you that particular injector is kaput .

If one is bad it's wise to test them all, out of the car .

FWIW : although it's best to only adjust them cold, Ma Mercedes was aware that hot adjustments would be done by necessity, that's why the original valve clearance sticker gave both hot and cold values .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better