Get rid of the "autolite" glow plugs and install some Bosch ones - accept no substitutes.

Last year, I obtained a set of Monark (or Beru, don't remember which) and 4 of the 5 died within 9 months. Pathetic.
Glow plugs either glow, or they don't there's not much of an in between.

Went back to Bosch and have been extremely satisfied.

My 84 300SD starts right up the in 9F (-12C) weather we've been having lately in Cincinnati - and the car sits outside (garage is full of building materials for my on-going home improvement projects).

Of course, I've got Mobil 1 0W-40 oil in there which I think really helps on those cold mornings.

Chris Blanchard
Cincinnati, OH
1984 300SD 165k