I am starting my first winter with a 78000 mile 1983 240D engine. I have trouble starting engine first thing in morn. It has only gotten down to mid thirties here, so I am wanting to learn more on cold starts. My first try after glow light goes out never starts engine. I turn choke on first and then try starting. It seems to flood out and then 2nd and 3rd try after glow goes off, starter will not engage or it seems glow plug is too hot or somthing like that. Usually on 4th or 5th try and turning off choke it starts and is beautiful sounding and running rest of day. Also maybe I need a more powerful CCA battery, I have a 65 rate now?? Please help a 240D lover and novice. thanks, ken...

Check your glow plugs. That is always the first thing to check when you start experiencing hard cold starts.

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I will need to find out how to check glow plugs and what to look for. I guess I will take to a MB dealer for my first check-up or tune-up. thanks again, ken...

1) Turn key to #2 position (glow plug light comes on).

2) Wait 30 seconds (ignore glow plug light)

3) Start engine.


The procedure will help temporarily, however, there are issues that may need to be addressed...........old weak plugs..........or low compression.

http://www.peachparts.com/shopforum/search.php

Don't forget that the valves need to be adjusted every year or 12,000 miles.

DO NOT, under any circumstances, take that vehicle to an M/B dealer. It's a certainty that they know less about the vehicle than any one of us and will end up charging you thousands of dollars to not fix the problem.

If you don't want to learn to do it from the info on the forum, find a recommended independent mechanic who works on these diesel engines regularly. Check the "good MB shops" forum right on the first page.

Start with things that are free!

I'm not sure what you mean by 'the starter will not engage' but I'd clean, and tighten all battery connections and ground straps.

you might try cycling the glow plugs 2x before trying to start the vehicle.

MBZ provided you with a beefy starter, you can run it for up to 30 seconds if need be, that a LONG time.

A properly sized and charged battery will help on those cold mornings.

Using gasoline engine terms in this forum will get you into trouble!

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Cheers,
Robert

Yes, I have a local MB repair shop that has been in same location for 42 yrs., He checked out my 240d before I purchaed it, so I will go back. ken...

There is no need to wear out the key cycling it. The glowplugs stay on for 1 minute or until the starter is used, no matter what the light on the dash is doing.

I mean that after glow light goes out on the 2nd oor 3rd try, when I try to turn key to right, I get silence, which I think means plug is too hot. Then I wait 30secs, and retry and it usually starts/works. What do U mean gasoline engine terms, so I will not make same mistake?? thanks, ken...

Ken:

1) There's no choke on a diesel. Are you referring to the idle speed control knob on the dash, just to the left of the steering wheel? If so that probably won't help your starting situation.

2) Change your oil and filter, refilling with 5W-40 synthetic. It makes a big difference. 15W-40 Dino is hard for the starter to crank, and you need the highest possible starter speed in the winter.

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'81 300CD - 180K, cannot be killed by any conventional means
'99 Ford Escort - good MPG

Lack of starter function has nothing to do with glow plugs or glow plug temperature. It is most likely a poor connection somewhere. It could be at the battery, a bad engine ground, or commonly in the ignition switch itself.
A diesel engine does not have a choke. You are probably referring to the idle speed control knob which does not choke the intake but turns up the idle speed.
Go to dieselgiant.com and follow his glow plug check sequence. You could easily have a bad glowplug or two. There are lots of threads here on lack of starter engagement in the 'start' position since it is a common problem on these cars.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Your car should definately start down to 0F even with conventional oil. The battery you want is a Group 49 which is about the biggest that will fit in the space.
At 30F you should be able to start the car with just the normal glow cycle, stomp the throttle to the floor 3 times then hold it half way and CRANK UNTIL THE CAR STARTS. None of this mamby pamby "I'll just crank for a few seconds" bs. The car gets harder to start each time it doesn't start.

If you still can't start at 30F with the above you probably need valves set and maybe have a glow plug out. IIRC you can have one glow plug out and the light will still come on. Valves first though, the starting will continue to get more difficult if you don't get the valves set.

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Sadly Benz-less

Press the accelerator half way and turn the idle speed adjuster knob counterclockwise to the stop. Then back off the accelerator.

(Read the attached picture)

Once started, turn the idle speed adjuster knob clockwise until the engine runs just smoothly.

Turn the idle speed adjuster knob clockwise completely to the stop not later than after the engine has risen to +60*C/+140*F.

Attached Thumbnails

 

In case you don't have the owner's manual, I'll quote from mine (300 TD, 1980).
"Engage parking brake or service brake before starting engine.
Place the gear selector lever in either "N" or "P" position before starting the engine. 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". Charge indicator and preglowing 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 glow plugs continue glowing for up to 1 minute, the engine can be restarted during this period without preglowing again.
Turn key clockwise to the stop to start the engine. Release key only when the engine fires regularly.
When the engine is at operating temperature (coolant temperature above approx. +70 C / +158 F), the preglowing indicator lamp comes on only briefly. The engine can be started immediately." End quote.

It goes on into more details, such as observing the oil pressure, not revving up high until oil pressure is indicated; don't leave idle speed adjuster up after engine will run smoothly.
"At ambient temperatures of less than -20 C (minus 20 C) / minus 4 F, depress the accelerator three times prior to starting."
When people refer to "cycling the glow plugs twice" it means two 40-60 second cycles. Pay no attention to how long the light stays on. I don't think there is any such thing as "glow plugs too hot". They get red hot when working properly. If you have the dome light on, you can see it get brighter when the relay turns the glow plugs off. You can also hear a click if there isn't too much noise around.
I strongly recommend getting a copy of the manual and reading it thoroughly, and read all you can on this forum...
Steve

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1980 300 TD

1997 Dodge Pickup/Cummins 5.9 12-valve