Down to about 0F is OK with an engine in decent condition with all the attributes mentioned above - good battery, correct valve clearances, good glow plugs and synthetic oil. Plus winter fuel and conditioner added.

When I lived in Ontario I didn't fancy going outside much below -10 or -15F, let alone starting any poor vehicle, be it gas or diesel.

How about leaving it idling all semester?

Sixto
87 300D

I concur with those who suggest making a deal with someone close to campus who will allow you to park-and-plug. A heated garage would be even better but those are probably scarce and expensive.

Additionally, get a trickle charger for your battery. That way, you will have both a warm engine and a fully charged battery; the waste heat from the charging process will reduce the risk of the battery acid freezing.

I suggest something like Harbor Freight Item # 99857, "1.5 Amp Three Stage Onboard Battery Charger/Maintainer" here. I have an older version of that charger on both of my diesels.

What will the campus do when people start driving electric cars onto campus and wanting to plug them in? I suppose as an oil state, they don't care.

Jeremy

__________________

"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

-40 with a 617? good luck.

Here is what needs to be in spec to maybe do that:

Compression, must be high, near new.
Valves adjusted
Timing spot on
Starter strong and fresh
Battery strong and new
Check all battery leads and ground, must be making good contact.
Synthetic oil, 5w40 in the sump so the starter can spin the motor over fast enough.
New glow plugs.


If everything is to new spec you have a fighting chance, the PO of my SD did a couple of -20, -30 starts with it when he went skiing but the car was only 13 months old at that point.

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

I'd imagine mine would start then... it starts like it's 70*F out when it's -15*F.

I wonder how long the glow plug light would stay on at -40*

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Make sure all gps. Work adjust valves and you can easily put a lower radiator hose heater in cheap and easy and an x-tra which I have done is put a wrap around battery blanket on. To use the heaters you have to have access to electric to plug in.

Many years ago, in Alaska, my Chevy truck had a propane heater to preheat the engine. It was inexpensive but that was years ago. Could there be something cheaper than a Wobasto? They do work well and can be programmed in advance. If you can afford one, get one. It will be easier on your engine and girls may be attracted to your car.

Many GAS cars won't start without heater/assistance at -40F because the battery will be too frozen to give any useful power to crank the engine.

A 617 is not going to do much of anything at those temps without a strong block heater AND battery heater.

If you are on college campus why do you need to be driving?

A portable generator powering a battery blanket and in-block block heater is your best bet....at -40F you're going to need to run it at least 1-2 hours to stand a chance is my bet.


Other options: dual larger battery setup with ability to switch to 24V for cranking bursts.

Better have: perfect compression, synthetic oil, perfect glow plugs, and recent perfect valve adjustment.

I'm also pretty sure even Winter diesel will be gel at that point without a healthy dose of additives or kerosene in the tank to prevent it.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

In my experience the OM 617 will not start below zero without being plugged in. The 603 I have never plugged in, and its always started. In Wisconsin it will occasionally get down to -20. I am about to go through my first winter with a 606. I have had no experience with it, but the block heater is still in factory wrap up, so it's never been used, so i suspect it will be fine.

__________________
1959 Gravely LI, 1963 Gravely L8, 1973 Gravely C12
1982 380SL
1978 450 SEL 6.9 euro restoration at 63% and climbing
1987 300 D
2005 CDI European Delivery
2006 CDI Handed down to daughter
2007 GL CDI. Wifes

Did you guys notice this thread is from 2011. The OP last posted February of this year. Maybe he'll swing by and tell us what he ended up doing. Before I noticed it was an old thread, I was thinking "Mongolian block heater".

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

Original post says:

So here i am planning on goin to college in Laramie, Wyoming. I want to bring my mercedes ('81 300SD) with me, but my parents, along with myself, have a cause for concern. It gets reallllly cold here... Like -40F cold..
#########


I call BS, -40 is very very cold.


Post 14 says: Yeah, it gets cold, but consider this: The average January high temp in Laramie is 32.7 degrees while the average January high temp in Stevens Point is about 23. The average lows: 7.8 in Laramie vs. about 3 degrees in Point (I got these numbers from Wikipedia/The Weather Channel sites).
####


Post 10 says

Small gasolene generator you've seen these tiny ones that are about a 1,000 watts looks like a big lunchbox with a pull start...(with synthetic oil in it) pull it out of your trunk plug the car in to it....or feed the power lines to your trunk inside. strap it down in the trunk....open the trunk lid.
#############

I was thinking the gen thing too but, do the running gen in a open trunk and you will look like his sig pic. Even with the lid open you can fill the car with CO. ( Yes I know that most MB have a steel bulk head between the trunk and cabin but is isn't air tight. )


In any event, you need good compression, do a test now and you might be looking at a valve grind to keep compression up.

Consider an intake air heater. These are used on direct injection diesels to provide heated intake air.

There are two types, a coiled element that looks like a massive spark plug. These draw ~ 30 amps. Another type is called a "flame plug" takes less power and uses diesel fuel to heat the intake.

Take a look at industrial diesel engines from Deutz , Hatz , Perkins. Also look at farm tractors from Ford , International and others.

Also consider a 2nd battery for more reserve power. If you can't get one with the same capacity / age , use a continuous duty solenoid to bridge the two when you have the key on and drop it when key is off. Batteries of different ages can discharge the stronger one into the weaker one.

Lastly, just plan ahead and use public transportation on very cold days. You are going to want to have this in place anyway for unseen breakdowns.

I know this is an old thread.......

I have a Webasto heater; just pulled from 1982 Euro 500 SEL. It will be for sale soon.

__________________
daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
No longer selling Cluster Needles Paint
No longer selling New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

nice!
PM me when you get it up for sale!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Many transit busses use a diesel fired Webasto heater. However they are 24 VDC so you will need a DC to DC converter.

If VS Tech chooses to pass, please shoot me a PM.

__________________
617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap