There should be about 13F outside tomorrow morning, when I will need to start my car ('84 300SD, OM617)...

So far, low 20s F were the lowest temps I tried starting in, and the engine has been catching pretty fast, with proper pre-glow - no hiccups or any need to throttle with the pedal.

My question is, can I get away with a couple 30-sec pre-glow cycles at 13F before trying to start, or should I plug the electrical cord on the engine into the wall? If the advice is the latter, can someone give me an idea as to how long I need to have the thing plugged in before attempting to start?

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84 300SD - bought in April '06 with 237,000 mi

If you have to be somewhere, then plug it in! It doesn't cost hardly anything to run the block heater.

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Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

You can leave it on all night, use a timer, or get up early and give it two to four hours. It won't hurt anything, won't cost but a few pennies, and will help the engine start more easily. Less wear and tear on the engine is always good.

If you have a trickle charger, put it on the battery overnight. A fully charged battery is always a help in starting an engine. The waste heat from the charging process also keeps the battery a little warmer so it works better. (Cold batteries lose some of their capacity.)

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I'd leave it on all night - not worried about the electricity cost for this. But I live in an apartment complex, so I'll be running an extension cord from my second-floor balcony that has an oudoor wall plug... I'm a little uneasy leaving it overnight, in case someone decided to be curious and do me some sort of "favor"... I guess I'll get up early and plug it in a couple of hours before leaving.

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84 300SD - bought in April '06 with 237,000 mi

The block heater draws about as much current as a 50 watt light bulb......so a weeks worth of use might cost you the equivalent of a Starbucks Latte Grande'. Still much cheaper than a tow......
When in dought ..plug in!

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

Yes, Plug it in! It won't hurt anything. It should be plugged in for about 2 hours. but leaving it plugged in all night won't hurt either. the electrical cost is minimal.

my car starts at -3 in new hampshire without plug in but they are all different and i have new battery and glow plugs
will be down workin in point pleasant nj next couple of months where are you?

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commercial fisherman diesel in my blood in my boats trucks and Dear old Dad has had me drivin them since i got my first license in 1968
1986 300 SDL 427654
1999 Chevy Crew Cab Dually 225423
1986 300 SDL 287000 Dad's
1987 190 Turbo 158000 Mom's (my inheritance)

Depends on the car, my SD will get at least 6 hours of block heater time if I want it to start tomarrow.

The SDL on the other hand would require me to wait until the GP light goes off then a quick turn of the key.

Depends on the condition.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

If you can plug it in, then why not.

Consider that:

Each compression cycle without combustion is un-burned fuel to contaminate the oil or dry the cylinder walls before the next stroke.

Harder cranking is higher current, faster brush/commutator wear in the starter.

Running rough/uneven is also washing the cylinder walls down with fuel and creating more soot for the oil.

And most important: plugging it in will give faster heat from your heater.

Even if it doesn't **need** to be plugged in, it certainly is easier on the engine, I plug mine in below about 45F just because I like those summertime instant starts (and because there's a plug in the garage for it).

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Gone to the dark side

- Jeff

My Mercs are parked in a garage, but I still like to at least plug the 617engines in if the temperature is below 35F. The only 'draw back' to doing this is that a weak battery could be hiding. Allow me to explain. I have been driving my 1981 300D daily for a while as the 1985 is getting repainted. My 1981 always starts quick in the morning at home and when I leave work in the late afternoon. A week ago I traded my car for a friends truck to tow my parts car home that I had purchased. The next morning I took the truck back and went to leave in my car. My friend does not have a garage so that car was outside. That morning was in the high teens and windy. I cycled the glow plugs and turned the keys. The engine did not start immediately, but I held on cranking for a few seconds excepting it to start. Well, suddenly I went from what seemed to be full cracking speed dropped down to barely turning the engine. All is OK now, but it is time to replace that battery. By the way...trying to jump start a diesel from a small non-diesel battery is a joke. My friend had a large engine starter. That took care of getting started in a flash. I am getting me one of those.

My S-10 came with a factory block heater. I plug it in during the winter as well just because I can and it allows for quicker warm up. I have also installed heaters in other gassers that I have had. If the temperature gets below 10F an engine block heater is a nice thing o have, especially if you vehicle is parked outside.

Block heaters draw 400 Watts, not 50. Radiator hose heaters (like the one Diesel Giant sells) for those who can't get the block plug out, draw 600 Watts. Either way, it's a lot cheaper than having to call a tow truck to get you started.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I'm in the vicinity of Trenton, NJ...

Single digits this morning... I decided to follow y'alls advice and leave it plugged in overnight... Glad I did! Easy start this morning...

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84 300SD - bought in April '06 with 237,000 mi

Mine didn't like it at 1*F this morning, I decided I'd let it sleep in, but it has started easily until this morning in the teens and 20's. I think it's time for a new battery though.

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1980 300TD-China Blue/Blue MBTex-2nd Owner, 107K (Alt Blau) OBK #15
'06 Chevy Tahoe Z71 (for the wife & 4 kids, current mule) '03 Honda Odyssey (son #1's ride, reluctantly) '99 GMC Suburban (255K+ miles, semi-retired mule) 21' SeaRay Seville (summer escape pod)

I just got my mercedes this month. It's a 1985 300TD. I had trouble starting it the first time, and have had no such trouble again until today. It was in the teens F this morning and I tried starting a few times, doing what the manual told me about pressing the pedal and I have had no luck. I tried warming the glow plugs a few times and starting afterwards but that didn't seem to help either.

I'd like to know if I have damaged my car. I've been going out once every hour to try to start it and still have had no luck and I think it is in the 20s outside now.

I don't know anything much about diesels and was told that this would be a good resource to try to figure things out.

I don't have anywhere to plug the car in. Any suggestions on what to do now?

Go to Diesel Giant's web page. Good write up on how to test the GP system. You may have a few GP's not glowing.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D