Tips for starting a OM616 in cold weather
 

Hello everybody,

I've got a 76' 240D with about 190,000 miles on it. I'm taking a trip across the country stopping along the way to camp, which means no plugging in the block heater.

This morning I had a little trouble getting the car started after overnight lows dropped to about 40F. After the glow indicator on the dash stayed lit for about 15s we'd try and start it. It'd crank a bit, but never actually start. We repeated this process 2 or 3 times and then pushed the car over into the sun to let it warm up. After sitting for about 15mins, we tried it two more times and got it running the second attempt.

From what I've read on the forums these cars should start without block heater assistance until the temps get down to the teens. I've read people recommend cycling the glow plugs 2 or 3 times until you try and start it. Should I be concerned about this draining my battery? The battery is fairly new, but certainly not new-off-the-shelf.

I'm always starting with the idle adjust at high, but would pressing the accelerator past that high-idle point help or hurt for starting?

A few more details about the car:
- I'm running 10-40 dino oil (not syth)
- just did valve adjustment before the trip
- remanufactured bosch starter just installed along with new flywheel (old wheel was all eaten up)

Should I switch to synthetic? Okay to begin adding it as I refill the oil along the way? Or do I need to do a full oil change? Driving across the country I'm consuming about a quart every 300m anyways...

thanks for reading!

Can be other things but the glow plugs may be the old style and aged. New pencil plugs with the correct diameter mounting thread are still available.

If you have the old style series glow plugs you will see curly wires between some of them. These tend to be resistant dropping wires. Too much heat energy then does not get to the pre chambers. It is lost on the jumper wires.

Installing the new pencil type plugs since they are no longer in series requires some rewiring of their hookup. Most people that have done this conversion have thought it really improved things.

I was also wondering if the car was starting with no actual glow plug cycle. Usually your engine would not in my opinion at the temperatures you quote unless in very good condition. It is possible though as well.

A preliminary test just in case you have one glow plug shorted out. Get a glow cycle going and measure for each glow plug heating up with hopefully a laser guided type temperature reader.

A base oil actual consumption rate of 300 miles per quart puts this engine somewhat into the fairly worn category condition. Have a look for oil leaks or the vent line from the vacuum pump having oil in it. Both these problems can drop the base oil level quicker and make the engine seem like a heavy oil user when it really is not.

Try a lighter weight oil like 5W - maybe it is 5w-15? Do not quite remember.

barry12345: The engine definitely has the older style glow plugs in it. I'm planning on upgrading to pencil once this trip is over. Engine is fairly worn, has a decent amount of blowby (the oil cap dances and then topples off when I run the ol' oil cap test)

I'll pick up a laser temp reader and make sure each plug is heating, probably a good tool to have in the kit.

The vent line from my vacuum pump is pretty black, not sure if that's from old oil or current. Guess I'd just pull the line off and look inside?

The engine had some leaks coming from the valve cover seal and oil cap, but Ive since replaced those and now have no visible oil leaks!

I really do not think that vent line should be black. There is a chance that at some time in the past the pump diaphragm leaked and was replaced without the individual cleaning out the line. Otherwise it exhausts the clean air to enable the vacuum pump to develop vacuum.

A totally intact diaphragm cannot leak oil from the mechanical lubricated supply into this line.

You are already into your trip it seems so I realize how difficult it is to deal with these things or to even check them out.

The oil youre using is a bit thin- is it Diesel rated? I used to use synthetic in cold seasons with my '79.

Ive recently come to the conclusion that its critical to seal the engine envelope..valve cove gasket, oil pan, the oring on the dipstick, front and rear mains, breather grommet, oil cap, etc. If the engine isnt sealed, you can be drawing huge volumes of oily air through the crankcase.

The plugs may not be the problem-with this sort of oil consumption, your compression could be low. What I would suggest is to do three consecutive glow cycles before attempting ti crank. And get some of these problems looked at when youu can.

THE FSM has a chart showing the glow plugs getting hotter up to one minute in the on position. They do not say turn off and back on... just leave it on for a timed 30 to 45 seconds and see if that allows it to start.

Upgrading to the later pencil type plugs.....and doing a plug hole reaming to be sure no carbon is blocking the effectiveness of the plug operation would be advisable.

As your engine wears... it is common to use higher viscosity oil to fill the extra space where the bearings are worn away.... be sure to use Diesel rated oil.... I use straight 40 wt Delo 400... a pretty standard oil for our diesels...

I haven`t delt with these older style Loop type Glow Plugs, but from what I
understand is, if one burns out, the rest are out also. Like the old style
Christmas Tree lights back in the 50`s.

Up grading to the pencil type large plugs as Berry mentioned is the way to go.
Here is what pelican shows.

1976 Mercedes-Benz 240D Base Sedan - Ignition - Page 1

If you are going to be in camp grounds, maybe take along one of those Honda
generators for your Block heater. They are really quiet.


Charlie


sent from my pos computer

If it's cold out, 5W-40 synthetic oil is a must. Anything thicker than that is too thick. I use Rotella T6 5W-40 even in the dead heat of Tucson summer. The parasitic loss to pumping oil is VERY evident between 15W-40 and 5W-40.

Other than that, you absolutely should switch from series gow plugs to parallel. Ream the holes when you do. Clean all of the electrical connections related to the glow plug system.

If you can boil a big pot of water over a camp fire and slowly pour it over the engine block, it'll warm up the engine a bit. If your engine has the mostly solid aluminum intake, you can take a burning piece of firewood and run it along the body of the intake to warm up the air and intake.

The name of the game here is to get as much heat into the engine as possible, and make it as easy for the engine to crank as fast as possible.

Pouring hot water on the block is very dangerous....
First of all... it is totally ineffective... because you have a water jacket between where you can pour water and where the heat has to be for it to have any help.. that is the Cylinder Walls ....
and you put enough to possibly do any good you would be taking a chance on cracking the block. There are some things like the injection pump which are so close tolerance that the FSM warns about things like spraying it at a car wash...

I think one suggestion is valid. Or worth consideration. A cheap generator if you know the block heater works.

Mainly because on a trip you have few cheap options. No tools and probably no access to parts like the special new glow plugs.

I wonder if using starter fluid would not be a valid option if you wanna get started in cold.

Yes... on the starting spray..... while the engine is turning over... meaning you need two people to do it correctly.... spray 3 seconds of spray into the intake tube with everything in place.. like the air filter...
Approved by moderator WHunter for anyone feeling skeptical and about to post that it will blow up the engine......not enough BTU's to harm it..... but well may start it....

Pouring boiling water on the engine is way less dangerous than Ether in the hands of a novice. There's no way pouring boiling water will ruin anything. It will add just enough heat to help. You know, where I'm from in Boston it gets cold enough that a cup of boiling water tossed in the air will flash freeze into snow.

I would not use Ether even myself because I have a tendency to over due things and I would not want to crack a prechamber. I think the other suggestions listed are much safer and should be used first before reaching for the ether.

Manny, you are completely wrong.

40 degrees is nothing. You shouldn't need to change your oil or put in fuel additive.

It sounds like you just need new glow plugs, and you might as well upgrade them while you are at it.

I've had two 300Ds started down to high single digit temperatures on the first glow cycle with no problem. As stated earlier an engine in good condition could likely start at 40 with no glow plugs.

Dkr.

^ The key word is "good" condition. He burns a quart of oil every 300 miles. That isn't good.

I don't think a prechamber IDI diesel will start at 40F with no glow plugs. You'll be cranking for 10 minutes.

If the engine is tired, it needs all the help it can get.

I tend to agree with those who are saying that the glow plug situation is probably where you should concentrate your efforts. My '79 240D used to use quite a bit of oil (along the lines of what the OP reported), yet with good glow plugs I remember being amazed that I could get it to start reliably in below-freezing temperatures.

Changing to the synthetic oil probably is a good idea, too. I've never needed it, but when you're running close to the edge you should avail yourself of every advantage you can get.

Kurt

Synthetic oil, however with that kind of oil consumption it is going to hurt!
Dual batteries are your answer, having a second battery will make a world of difference. Deep cycle ones are a bonus. Or a boost with REALLY good cables and clamps that are not rusty, 0 gauge wires. Cranking speed is the biggest issue with cold starts usually.
Once back test your injectors, poor spray pattern can really hurt cold starts with a tired engine.
Light a camp fire under the engine, that is what they did in the old days at the ski hills to fire up the diesel powered lifts, or move hot coals under the oil pan for a while.
I have never liked using starting fluids, hard on the engine makes it want to fight internally. Hot water can work if you have the means of boiling enough, but it takes a lot of water to warm up a cold engine.
Webasto heater?

Synthetic oil actually burns off less than conventional oil. That's why high mileage oils are synthetic blend or full synthetic now. GIII & GIV basestock is much more tolerant of bad rings.

Listen up people....
CAST IRON is bad about CRACKING if heated or cooled unevenly.....
do not pour hot water on the block..
or the IP....
boiling water on the outside of the engine will not warm up the cylinder WALL ...which is what needs to be warmed......
WHunter.... esteemed moderator confirms that a three second shot of starting fluid sprayed into the intake when the engine is turning over... will not harm the engine...

I'd take boiled water on a campfire over walking miles to get starting fluid. If cracking was a problem, you'd think the head would crack as soon as the engine started and a 1000* F flame front hit the combustion chamber.

Manny, LISTEN UP....
I am telling you that the hot water on the outside of the engine will not help starting the engine...
it will only put you at risk of cracking the block...
I have asked you this before... How old are you?

As usual, back to ad hominem falacy. You give yourself away Greg.

I'm sticking to my guns. If cast iron cracked so easy it wouldn't be used as a cylinder head. All the people who degrease their engines while warm would have split blocks. Seeing as it isn't the case, I beg to differ.

i've never seen anybody trying to start an engine in cold weather by using boiling water. I have seen a truck driver that started a small fire underneath the engine in extreme cold weather and get it started that way.

A late friend of mine who used to be a truck driver and he used starting fluid to start his semi in sub zero temperatures. He used a lot of it.

A bottle of it costs few bucks and can easily be stored in the glove compartment.

Just saying.

Notice in these references the emphasis on the slow heating and cooling processes used in working with cast iron.. either out of the furnace or when trying to weld it...
it is the UNeven heating or cooling which causes it to crack or break...
There are many threads on this forum about cracked heads.... uneven torquing of the head bolts, misplaced cooling passages... or need for more coolant flow.... our 617 engines have three different changes to the holes in the head gaskets..., may be at fault.... The entire cooling system design is based on keeping that high heat from the actual combustion evenly distributed around the metal parts of the engine...
Take a look at these cast iron blacksmith post drill flywheels.... they were cast with ' fancy spokes ' for a reason... because without proper ovens to cure those castings in they would have broken if cast with straight spokes... so it was cheaper to cast those curves into the parts than to cure them slowly.
Notice that something as small as hardening the valve seats can set up stresses which show up later as cracks in cast iron heads....

https://www.google.com/?gws_rd=ssl#q=blacksmith+post+drill

Blacksmiths Post Drills, Acme, Champion and Buffalo Forge.

Cast Iron

Guidelines for Welding Cast Iron
"""Broken cast iron parts are not unusual, given the brittle nature of most cast iron."""

http://www.heat-treat-doctor.com/documents/castirons.pdf

Why did my pan crack?

Cylinder Head Crack Repairs - Engine Builder Magazine

http://www.locknstitch.com/pdf/gmrc_white_paper.pdf

Fundamentals of Professional Welding

https://en.wikipedia.org/wiki/Tempering_%28metallurgy%29

but the main reason not to waste that water is that it will never be able to put any heat to the cylinder walls where it would be effective in helping to start the engine... whereas using a block heater will surround the bore with warmth. As is.. it serves as an insulator keeping hot water on the outside of the engine from getting to the cylinder..
Manny is too young to understand this stuff.. so this is for others reading who might think not replying indicated his argument held water ( pun ).....

I don't want to get into specific energy about water and cast iron etc.

I wash my engine very often to keep it clean, and I have an even worse combo (Iron block Aluminum head) than 61x engines. No cracks here, because you need to heat and cool cast iron by hundreds of degrees RAPIDLY to crack it. I'm not saying "pour molten Sodium over the engine to heat it up." If cast iron cracked simply due to localized heat it wouldn't be good as an engine material.

Fools age too Greg (not everyone becomes wise as they age). :) The age falacy is still irrelevent to the question of helping a stuck diesel owner in the cold here.

Use a flame!

https://www.youtube.com/watch?v=LVxaJJhXofA

Short term:
Ether can be used in small amounts, but it's either ether or glow plugs, never both.

Best long term solution:
#1-Make sure valves are adjusted (free if the valve cover gasket isn't shot)
#2-Make sure your battery ground, battery hot, and block grounds are clean and connected with a bit of grease.
#3-Make sure the glow plugs are working
#4-Spend the $150 on a new high quality battery if it's questionable.



My best advice for starting any old diesel:You only get one shot in the cold. Hit the glow plugs, then hold the starter until it starts or the battery dies. The MB starters are rated for something crazy like 30 seconds on/ 2 minutes off. 30 seconds of cranking feels like an eternity compared to your average gas car(1-3 seconds).

Our cars have different type of diesel than most trucks.

It is NOT a good idea to use starting fluid.

Good earlier thread on subject.

Having said that, I have once or twice in an emergency squirted a 1 or 2 sec burst into air cleaner intake while cranking with battery boosted from another car. Hated to do it though :eek:

You are saying Whunter is wrong.

I'll second the do not use hot water sentiment.. It won't work, it can't work. The few seconds that the hot water will be in contact with the engine will not do anything more that warm the outer 1/16 of the metal it come is contact with. Its far more likely to get into somewhere it shouldn't be and ruin something than it is to help. Just don't do this.....

As others have mentioned your efforts should be focused on a few basic winter diesel measures, ie) adjust the valves (often over looked by people, it can make a huge difference), glow plug upgrade, and a thinner diesel rated oil.

Ether in VERY small doses can be used, but I would not do so without unhooking the glow plugs first. Somebody previously in this thread likened its safe use to that of a tractor trailer driver he knew, this is a bad comparison. The big diesels in trucks have very little in common with the engines in our cars, they both run on diesel, but that's about where the similarities end.....

That said, I would not resort to ether unless it was an emergency situation, and even then I would think hard about it.

A second battery is a good idea, however don't use a deep cycle as was previously mentioned, they are not designed for the rapid drain and high draw that starting a car put on a battery. They are designed for a slow continuous draw. A proper car battery is a better choice and should last longer.

Finally, the small generator is a really good suggestion. If your stuck somewhere and its cold, pull it out of the truck, plug in your block heater and fire it up.

If I were you though, I would do the glow plug conversion before heading on your trip, as well as the oil and the valve adjustment. All three of these can easily be accomplished on a weekend with basic tools (although a set of bent valve wrenches make the adjustment easier). I would also consider an extra battery....

No idea what Whunter says on the subject.

But did do a search. Seems he and I agree?