123 Owner's Manual-Winter Starting Instructions (1980)
 

Since there have been a number of cold weather starting posts, it piqued my interest enough to go read what my Owner's Manual actually said. While I've owned diesels before, I am a vintage Benz diesel newbie. That said, this is for the 1980 model year. Whether or not newer 123's are the same, I don't know. Not yet, but I will :) So for any newbie without a manual and were curious as to how MB recommended winter starts, I offer this:

With the engine cold, depress accelerator halfway and turn idle speed adjuster counterclockwise to the stop. Then release accelerator.

Turn key in steering lock to position "2" (run position). Charge indicator and preglowing indicator lamp must come on.

The preglowing process then begins. The engine can be started as soon as the preglowing indicator lamp has gone out. Since the glowplugs continue glowing for up to 1 minute, the engine can be restarted during this period without preglowing again.

Turn the key to the stop to start the engine. Release the key only when the engine fires regularly.

When the engine is at operating temperature (coolant temperature above approximately +70*C/+158*F), the preglowing indicator lamp comes on only briefly. The engine can be started immediately.

At ambient temperatures below 0*C/32*F and with the engine cold, completely depress the accelerator while starting. Actuate starter until the engine fires regularly and the engine speed rises. Then ease off the accelerator slowly. Cranking times of up to one minute will not do any harm to the starter.

At ambient temperatures of less than -20*C/-4*F, depress the accelerator three times prior to starting.

Idle Speed Adjustment:

Turn idle speed adjuster clockwise until the engine will just run smoothly. The idle speed adjuster should be turned clockwise to the stop (normal position) at latest when the coolant has reached a temperature of +60*C/+140*F.

I hope that helps someone.

REEEELLy?
according to the "flood diesel" thread, pumping does nothing... who is correct?
John

Verbatim.

I was surprised when I read that, too. I wonder what the three pumps do? Help prime the injectors given the thicker fuel?

I'm guessing MB is correct in their manual? Maybe it's one of those German->English translation things. Similar to Chinese->English except without humor. :D

Maybe it gives the injector pump a kick in the pants to loosen up the governor parts in verrrry cold weather.

I don't have an idle speed knob, its in a picture in my manual, but I don't see one in my car. Also, if I crank the car and it doesn't start, I have to take the key completely out, then there's a click, then I can try cranking again.

Everything else I follow the instructions and it seems to start fairly well in the cold. I would like to get my block heater working though...anyone have the diesel giant lower hose heater? Does it heat the coolant just as well as the original heater?
Thanks,
-Geoff

An idle speed knob sounds great. Is there one hidden somewhere in an '83 300SD? What does it look like and where is it supposed to be?

BTW. It was 12*F overnight and about 20*F this morning when I started my car. Took two tries, but if I kept it going the first time it probably would have started after about 10 seconds of cranking. Not plugged in, not bad.

I remember when I was a kid I had a friend who "knew about cars" that told me people with diesels had to go outside on cold mornings with blowdryers to get their cars started. :D

chef, while your thinking of it, click on the 'User CP' tab above then go to the 'Edit Signature' tab and put your vehicle info. into your sig so that those-in-the-know can help you with your questions (of which I'm not one :) ). Some may be model specific.

Seems like quite a few have the lower hose heater and are happy with it.

Nope... supposedly automatic, but my 82 needs my foot on cold mornings to keep it happy...
John

Turbos dont have the idle adjuster and dont (shouldnt) need it. Only NA have it.

yea i was shocked when i got my 300D turbo, since its my winter car i thought id use the idle speed knob more than in my 240D. but when i got it, i saw that it didnt have one:( but the idle speed knob is right underneath the gauge cluster to the left of the steering wheel

See, learnin' already! :)

Done...but I guess it isn't retroactive on prior posts...we'll see when this one goes through...

So, anyone have the Diesel Giant lower radiator hose? Is it awesome? Heat the engine sufficiently?
-Geoff