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Does a diesel mercedes need a block heater in NC?

I have a 85 300sd and moved from LA to NC. now it is cold, do I need a block heater? thanks!

In the mountains, maybe. In Cary NC, no.

Unless it has 462,000 miles on it. Then it needs all the help it can get…

My 300D (same engine) has 412K miles at the moment and I don’t bother plugging it in unless it’s below about 15F. I have started it at about -5F without the block heater plugged in, but that’s getting near the limit. You need a strong battery, good starter, 5 good glow plugs, 5W40 synthetic oil (mobil 1 or shell rotella diesel), and correctly adjusted valves. A cetane booster doesn’t hurt in very cold weather. Many of those engines were delivered with the block heater installed but not the cord. Look on the right side of the engine, above the starter to see if it’s there. If so, you can just buy the cord:

Where you are moving to, you don’t normally need a block heater to get the car started if everyhting is working well. However, I would still recommend it since you get quick warmup, less engine wear and slightly better fuel economy. Most Mercs shipped to North America were assumed to operate in colder parts of the country during their life, so they had block heaters installed.

That’s good advice, it does save a lot wear and tear on the engine starter and battery, it’s also nice to have cabin heat right away. One caution, it your engine doesn’t have a heater installed, it can be a real PITA to remove the block plug. Some folks choose to install radiator hose type heaters instead (not as effective, but better than nothing).

Block heaters are not necessary here in NC. It just doesn’t get cold enough for that. We work on lots of diesels. Not needed. One thing that might ease the starting is to make sure it has the newer quick-cycle glow plugs and relay which warm up much faster. An older '85 like yours probably has the old slow cycle circuit. you can tell by how long it takes for the glow plug light to turn off. The improved kit should only take about 5 seconds or so.

The only real upgrade available for that car is the “post-glow” type relay that keeps then energized for a little while after the engine starts (smoother running, less smoke). They still need to glow for about 15 seconds in cold weather.

? it doesn’t snow in NC?

have you actually looked in the manual, and under the hood. i would be surprised if it didn’t have one; but just tucked, folded away somewhere in the front of the engine compartment near the radiator.

It snows far West in the mountains some, but most of the ski slopes have to use man made snow machines. We’re not quite North enough. We might get a storm once a year with snow for a few days across the rest of the state. That’s all… RARELY do our overnight lows get down in the 20’s. That’s why we usually are fine with a little thicker oil year round too.

no just buy winter diesel…thats ok to minus 40-c