I had my 2.2L engine and it started in the Montana Rockies without a block heater, but during the real cold times (-28 F), I had to double bump the good glow plugs and spend a deal of time getting it running. The rest of the time, it started OK, just took a little longer to heat up.

I bought an aftermarket heater for my 300D at Napa, and took it in for installation to a local shop in Fergus Falls, MN (Near Fargo, ND). I gave them a printout about the sage advice from others in extreme winter enviornments about putting in an OEM block heater (requires a torch applied til bolt is glowing red), but the mechanics would not listen and insisted on installing the OEM, which was available. After I said OK, on the basis that they give me a written estimate on time, they vowed to start it and have it finished in the morning. Well, what do I know . . . am just a woman and just a dumb truck driver. They didn't even want to read the info from here on this forum warning about the OEM black heater on an older car. Well, guess what . . . . they were not happy to see me the next day. They finally had to read the printout and fire up the torch, and I had them stuck on that written estimate. My advice . . . use the one that you have until it burns out. Replace it with OEM if the bolts are not welded on from time, or get the aftermarket replacement if they are as good as welded on.

Every winter that my 300D spent in Fargo area cost me a new set of glow plugs. But NYC was a piece of cake, even on the coldest days.

Torie

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1983 300D, the "Avocado"
1976 240D, 4-spd the "Pumpkin", SOLD to Pierre
1984 190D, 2.2L, 5-spd, my intro to MBZ diesels, crashed into in 2002