OM615 Mercedes: 2.2L Engine Starts Poorly, Smoking

Hello,

It's about an old, 2.2-liter Mercedes pre-chamber diesel engine that's installed in a tractor.
The engine is installed, and it's designated as the OM 615.918. I believe it was also used in the older W123 models.
The tractor has been sitting in a shed for almost 5 years, and I'm currently in the process of getting it back in working order.
I don't know anything about the history of the engine, so I don't know if these problems existed before.
If you let it glow for long enough, the first ignitions will happen quickly, but without adjusting the gas mixture, the engine won't run smoothly on its own.
If it's a bit warmer, it will probably start on its own, but it seems like it's about to jump right out of the car.
The engine is shaking very violently. However, it still responds well to acceleration and drives well.
When idling, it emits blue smoke from the exhaust. However, as the temperature increases, the smoke becomes less noticeable.
I hope that someone here is familiar with the older Mercedes engines and can perhaps give me some advice.
Common rail injection pumps are completely new territory for me.
Perhaps it would be worthwhile to have the fuel injectors tested, or are the symptoms not typical of faulty injectors?
Does anyone have a diagram or overview of the adjustment screws on the pump?
I still need to check the exact name/designation.

Hello Oliver,
Does the pedal provide a stable idle?
Best regards, derteileklaus.

Hello Teileklaus,

Thank you for the response.
I just took a look at the engine, and I have to say that it's in a very bad condition.
I adjusted the valves because almost all of them were completely tight, and in the process, I found a lot of oil sludge in the valve cover.
The oil appears to be very old and has left a nice, black sludge behind.
I started by changing the oil and replacing all the filters.
The thermostat is also broken; it's always stuck in the "off" position, which prevented the engine from warming up.
It's been ordered and is arriving tomorrow.
We'll drive with this oil for a while now, and then I'll probably have to change it again. Hopefully, this will get rid of the sludge!
I couldn't get it to start properly when the engine was cold. If the thermostat is new tomorrow, I'll try running the engine from a cold start again.
It seems to me that the idle speed has become much smoother. Perhaps it's due to the valve adjustment?
You can stabilize the idle speed by giving it a little bit of gas.
Just now, I also noticed some brief interruptions.
When the engine is running, the sound of combustion briefly stops, the engine jerks slightly, and then continues running.

Great!
Check if there's an idle speed adjustment screw somewhere in the steering wheel area.
Turn it completely to the right, clockwise. If nothing changes, rotate the casing on the motor to increase the speed.
Die Aussetzer sind warscheinlich ein anderes Problem. Stopper?
A low RPM can be explained by "incorrect valve clearance."
But besides fleas, the dog could also have ticks at the same time!
derteileklaus

Hello,

Are the interruptions permanent, or do they only occur in the first few minutes?
Then it could be due to the spark plugs.

Best regards, Rodion.

Hello,
Regarding your glow plugs: my understanding is that the 123 model uses glow plugs connected in series.
Either all the lights turn on, or none of them do. You've checked that, right? So, there's voltage at each candle.
available?
"Older diesel engines often have a low idle speed when cold, so they are frequently adjusted using a throttle cable adjuster (models 123 and . However, if the engine is adjusted and still experiences misfires, there is likely another underlying problem."
If the valves were too tight, a compression test would be necessary.
(Is the valve burned out?)
"The oil consumption during the initial warm-up phase is normal for a car of this age, as long as it stops once the engine is fully warmed up."
derteileklaus

The blue smoke from such an engine can also be caused by poorly adjusted or defective injectors. It would be a good idea to have them checked.
With the Oelpampe (a type of oil filter cleaning device), you can extract the used oil during oil changes, doing multiple extractions in a row, each with a filter. Use it until the oil turns black again, then extract the "broth" again, and so on.
If the engine has been idle for a long time (5 years), it's possible that some of the piston rings may become slightly stuck and no longer seal properly. However, this should gradually improve after several trips and with fresh oil.

Hello,
Thank you for the answers.
The misfires only occur shortly after starting the engine. However, the glow plugs are fine; I've tested them individually.
The engine already has a parallel wiring configuration for the glow plugs, instead of the previous series configuration. However, the glow plug monitoring system is still installed.
Since the glow plugs don't have a post-glow function, isn't it normal for the engine to be a bit rough at the beginning? After all, the plugs turn off again after the start.
Is it worth upgrading to fast-glowing spark plugs with an afterglow control unit?
The preheating has been going on for quite a while.
I've already driven a bit, and I have to say that the engine is running better now.
The smoke is almost completely gone.
Is it normal for the engine to occasionally make a loud knocking sound?
The knocking sound occurs intermittently while the engine is idling. It happens for a few ignition cycles, then stops again.
I'll probably test the nozzles sometime next week or the week after. I'm curious to see what the results will be.
At the same time, we'll put in some new oil with a new filter.

Hello,
If the nail starts to lift immediately after being applied, you could try to re-adhere it manually.
Then you'll see if the aftertreatment system is working properly, but still have the injectors checked.
Best regards,
derteileklaus

So, if my engine ever starts misfiring...
'...then he adds 5 liters of a mixture of petroleum, gasoline, and 2-stroke oil, each in a 1:1 ratio, to the empty tank.'
If you don't beat it up, it will be scratch-free again after rinsing.

Hello,

Is this mixture supposed to clean the fuel injectors, or where does it work?

Hello,

Unfortunately, I don't have the resources to conduct explicit research.
But, based on my experience, this process cleans the entire fuel injection system.
I'm also thinking specifically about the fuel injectors.
I use gasoline mixed with rapeseed oil, and occasionally soybean oil.
It's likely that the nozzles will become clogged, etc.

Best regards, Rodion.

Hello,

What else I was thinking... It's possible that the fuel injection pump still has its own oil reservoir.
As far as I remember, the ESP (Environmental Protection System) wasn't connected to the MÖL recycling system until the mid-1970s.

Best regards, Rodion.

Hello,

da könntest Du recht haben. Oben auf der ESP ist so ein großer roter Deckel. DIt's covered in oil.
How do you check the oil level, and what type of oil should be used?
Regular motor oil?

Hello,
The dipstick is attached to the red cap.
Engine oil refill, if I remember correctly.
Best regards,
derteileklaus

Hello,
I was on vacation for a few days, so things took a little longer.
I just took off the red cap. But there's no measuring stick attached to it?
If you look into the hole, you only see a few smaller holes, nothing more.
How can you check the oil level there?