I recommend that your next step be a rebuild of the delivery valves (new O-rings, copper washers, and new springs). Research the procedure, ask questions if needed. Special socket required for the delivery valves, and a torque wrench for the 30 Nm then release then 30Nm then release then 30 Nm then 35Nm torque sequence.

What does the exhaust smell like? Raw diesel fuel is pretty easy to detect for me. Given the low oil usage, I'm pretty sure you are not loosing oil out the rear of the turbo.

Probably left over from before you blocked the EGR, unless you cleaned it then.

That is my opinion, but others on this board disagree with me. Again, given the very low oil usage, I don't think this is your issue.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

My 432,000 mile SDL # 14 head motor will smoke at tad at startup & I go through (burn / leak) 1/2 qt. of dino oil per 3,500 miles.

What I do know is that the initial startup smoke is somewhat proportional to the amount of time the car sits. I.E. just a little smoke or non-noticeable unless I'm glaring at the pipe in between multiple starts with in a day.

On the other hand, if I let the car sit for a few days I'll get noticeably more oil smoke at start up. My studies suggest that the valve seals are tired. They're the original 30-year-old seals and rubber seals deteriorate. Gravity allows for a little oil drain into cylinders or on top of valves prior to opening, not necessarily a vacuum thing.

I did notice this scenario was more pronounced with synthetic Mobil oil. I'm now back to running Rotella 15-40wt.

I had the cam off a while back to replace the lifters. Even purchased new valve stem seals...but in the end I decided not to screw with the seals and potentially get into more trouble. Remember valve stems may also not be supper new smooth and result in minor sealing faults.

You have a newer/old motor. Rubber is old regardless of miles, just like suspension parts. I think that your newer/old motor just needs to be run, and run, and run…maybe with dino oil.

Handle the smoke issue administratively...i.e. wait until folks have cleared the rear end prior to firing it up LOL

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1986 300SDL 440,xxx

Thanks for the advice, the exhaust doesnt smell like oil, or unburnt fuel, it actually smells relatively clean for an old diesel. I did clean the intake out after removing the egr so I think the oil is fresh. As for the delivery valves, how would I find replacement springs? I didnt know they were a wear item. Also, are you talking about the reseal procedure, or is a rebuild more involved. I have read loads of threads regarding resealing the valves but none about rebuilding them. Since mine are dry, I never bothered to reseal them yet. Could they be bad without leaking?

Heres an update to the situation, after some more testing with someone else revving the engine I have found that the smoke is least at idle, and gets heavier as the engine speed increases, its blue grey smoke that looks black in the right lighting. I just don't notice it when the car is moving when I am driving. Also, the smoke completely stops when the accelerator pedal is released, then starts again when the engine returns to idle. What does this mean? It makes me think its fuel related smoke, because it stops when the fuel is cut off momentarily when the throttle is let go. As for the delivery valves, I pulled one off and the oring seal looked as good as new, so I didn't replace the rest, as they were not leaking. It seems to have the symptoms of timing being off, but I checked it and it is spot on. I am almost thinking of moving the pump slightly to see if it has any effect. If this was oil smoke from the rings or valve stems I would think it would smoke all the time no? I'm sure this certainly rules out the turbo seals.

If your air filter is older. Remove it and run the car without it as a test. I imagine you already have covered that possibility very early though.

Yup Ive got a new filter installed as well. Also just got done checking the air flow sensor in case the door was not opening, but its working as it should. The only thing left is the injection pump, which I never thought would have issues as this mileage, but now im thinking of sending it out for calibration. Especially since I'm almost sure this is fuel related now.

Interesting

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check out Servicing Stop as they fix anything and everything to do with cars and have a brilliant service, they pick your car up, fix it and drop it back off! Plus 50% off your service!

I think you may have some dried out old turbo seals. My 432,000 mile SDL does the same as yours. Tell tale sign is the presence of wet oil in the charge pipe as you have noted previously. Old valve seals seem to also produce a little smoke.

I have the same minimal smoke (blue/gray) issue. I don't seem to loose / burn much oil i.e. 1/2 to 3/4 qt. per oil change.

We've had the car since new and I remember some 30 years ago bringing the car into the dealer asking about the small amount of smoking. Response was...that is normal. I have always seen some "haze" in the rearview mirror at night in headlights when pulling on to the freeway or otherwise romping on the motor.

Excess black smoke is more a fueling thing. I've periodically cleared that problem with injector service, alda adjustments, IP air filters, delivery valve service, and so on.

Almost forgot....once replaced the cat converter down wind of the flex pipe made things better for 75k or so. I removed it after it clogged up a second time.

One last point that is fuel related is that I've been running a few ounces of 2-stroke oil per tank....and like my old 2-stroke motor cycles...ya see a little blue grey smoke. I prefer a little smoke knowing the fuel system is getting adequate lubrication.

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1986 300SDL 440,xxx

The Mercedes Service Manual only covers how the tool is used to lock the Fuel Injection Pump before you install the removed Fuel Injection Pump.

That means there is a need to understand how it works. Inside of the Pump on the Governor Weight Carrier is a tang; sort like a screwdriver blade tha point outward. That tang rotates with the Governor Weight Carrier and can be seen when you remove a Plug on the side of the Governor Housing.
That is the same hole that the Timing Locking Pin screws into.

The Timing Locking Pin has a bevel on the Plunger so that the when the blade comes around the plunger can be depressed agaisnt spring tension. A cross the diameter of the Timing Locking Pin Plunger is a groove that is supposed to catch the blade and stop the Fuel Injection Pump from rotatint.

In order for the Timing Locking Pin to lock you need to make sure that the slot on the Timing Locking Pin is oriented to catch the blade and to do that there is also a slot you can view from the outside of the Timing Locking Pin so you can tell the orientation of the slot.

The first pic shows the hole and blade
The second pick is a drawing of what things look like inside when the Timing Locking Pin is locked in place.
The third pic shows the Timing Locking Pin oriented correctly so the blade will catch it.

To check the timing you will remove the Plug on the Governor housing. Manually rotate the Engine in the directio of rotation till you just barely see the Blade as viewed through the hole. Stop there and install the Timing Locking Pin.
Very gently manually rotate the Engine in the direction of normal rotation till you feel resistance to it turning (if you use too much force even though the blade is caught in the slot of the Timing Locking Pin you can depress the spring and actually over ride the slot meaning you can go too far if too much force is used.)

Stop there. Check on your emission sticker for the timing. Note that the Timing is After Top Dead Center. In general the Engine timing when new would have bin 15 degrees or 14.5 degrees ATDC but you need to look on the spec on the Emission Sticker to be sure.

Attached Thumbnails

     

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84 300D, 82 Volvo 244Gl Diesel

Re-timing if your timing is off most likely late/rearded.

You would remove the Timing Locking Pin and manually crank the Engine in the direction of normal rotation so that the blade viewed through the hole dissapears and keep cranking till it just barely comes back into view.

You re-install the Timing Locking Pin making sure the slort is oriented as it should be to catch the balde.

You then are going to manually rotate the Engine in the direction of rotation till the timing degrees on your emission sticker line up with the Timing Pointer. Stop.

I have usally fournd it is easier to rotate the Fuel Injection Pump with the Fuel Injection Lines Loose so in my case I loosen those either at the Injectors or the Fuel Injection Pump. Then you need to loosen what ever bolts our nut keep the Fuel Injection Pump from rotating.
Then you gently rotate the Fuel Injection Pump till the blade locks in the slot. However, remember you need to run the blade past the bevel and push against spring tension before the blade gets to the slot so expect a little resistance as the blade depresses the spring.

On my own 617.952 rotating the top of the Fuel Injection Pump towards the Engine Block advances the timing.

When the blade is in the slot locked I forgot to mention that the Plunger also protrudes more towards the out side. Mine had a painted area or some sort of mark to show when it was protruding enough.

Onece the blade locks in the slot tighten down the Fuel Injection Pump so it will not rotate.
Remove the Timing Locking Pin and take a look at the blade as viewed through the hole and you should see the blade centered in the hole. Re-install the Plug and connect up anything else you removed or loosened.

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84 300D, 82 Volvo 244Gl Diesel

Thank you .

Every emissions sticker I've ever seen in an OM 617 says time to 24° BTDC .

I'll find a printer and try this method you're describing and see if it helps .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Thanks for all that information, I ended up checking the timing as described and found that it was spot on. However, yesterday I removed my alda to see what effect that would have and found that the rod that the alda presses on to limit fuel was actually stuck in the down position. I was able to free it by removing the clip that holds the spring and moving it up and down. It drives like a whole other car without the rod in the down position. But, unfortunately the smoke is exactly the same. This has me thinking about sending the injection pump out to be checked or rebuilt if necessary. My thinking is that if this rod was jammed, maybe something else internally is jammed as well, possibly affecting the timing slightly, and just about everything else has been checked. The P.O. did tell me he had to replace the fuel lines and have the fuel tank boiled.

Well I might pull the tube connecting the turbo to the intake. Just to make sure you do not have a little leakage and running the engine at idle without it as a test.

Really though I would drive it for awhile. It is the early 603 and they sometimes breech their head gaskets between the oil feed passage to the head and the first cylinder. I think they improved those gaskets pretty early. The real problem to me is the oil passage is too close to the front of the number one cylinder.

If I am right in service it should get worse with time. I might consider leaving it alone for awhile to see. That is just me though. I certainly would not pull the head until the first cylinders injector or glow plug appears oily compared to others. Eventually this usually happens. I doubt you are leaking enough oil there yet to tell if it were the problem. Head gaskets age out as well as this is not the best design.

Checking the injection pump timing is probably about the only other thing I would consider at this point. Nothing will get hurt by driving the car if it is the head gasket. These engines never seem to hydro lock with oil.

This is a pic of the emission sticker from my 1984 300D with 617.952 Engine.
The parts circled in red have to do with the other timing methods that use the Governor Housing Plug Port and refrence on the Blade inside on the Goveror Weight Carrier whic includes the timing locking pin.

If you look in the instructions on how to use the timing locking pin it tells you which degrees to use.

The other timing method in circled in Yellow is what we refer to as the Drip Timing or Flow Timing.

I mentioned the emission sticker because some of the Mercedes 6 cylinder Diesel Engines don't have a spec for Drip Timing and the spec may not be 15 degrees ATDC + or Minus 1 degree. On some of them it is 14 something degrees ATDC.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

" If you look in the instructions on how to use the timing locking pin it tells you which degrees to use."

The tool doesn't include any directions , how I wound up here .

I'm keen to find a printer and give this a go .

I have a 1984 300CD and it had a different sticker on the rockerbox , in time it turned brown and crumbled away .

Again ,

THANK YOU to all who posted ! .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better